Correct Answer: A. Normal bruising from toddler activity ✅

Detailed Explanation:
Bruises over the shins of a healthy, mobile toddler are almost always due to normal active play and minor knocks encountered during exploration (“toddler bruising”). In Australian primary care, it is well-established that after mobility is achieved (walking confidently, usually from 1 year), minor bruises over lower limbs are a physiological finding. They are not typically concerning if symmetric, found over bony prominences (such as shins/knees), are few in number, and not associated with any systemic features (such as pallor, organomegaly, bleeding elsewhere, or unexplainable injuries).

• A. Normal bruising from toddler activity: Supported by population studies and guidelines (RACGP, Child Protection Australia). Bruises over the front/side of shins and knees are frequently noted in toddlers and primary-school children. Absence of other features (such as high-risk locations, concerning patterns, or developmental delay) makes this the most likely and benign diagnosis.

• B. Signs of non-accidental injury (NAI): ❌ Child abuse must be considered if bruises are in unusual locations (e.g., buttocks, face, trunk), are of suspicious shapes (handprints), multiple, in various stages of healing, or inconsistent with the developmental stage. None of these are present here.

• C. Vitamin deficiency: ❌ Bleeding/bruise patterns from deficiencies (e.g., scurvy, vitamin K) are rare in healthy children on a normal Australian diet, and would not be restricted to shins nor be the only presenting feature.

• D. Coagulation disorder: ❌ Conditions like haemophilia or ITP typically cause extensive, larger, or spontaneous bruising (sometimes with mucosal bleeding, petechiae), and/or a relevant family history. Normal growth, activity, and absence of systemic/bleeding signs argue strongly against.

• E. Allergic reaction: ❌ Allergic purpura or vasculitis usually causes palpable, sometimes painful purpura, not non-tender simple bruises.

• F. Eczema-related changes: ❌ Eczema causes itchy, dry, inflamed patches—rarely associated with simple bruising.

• G. Insect bites: ❌ May cause papular urticaria, but not typical bruises.

In the context of this scenario, further investigation or referral is unnecessary unless there are future signs of systemic illness, coagulopathy, nutritional deficiency, or patterns suspicious for non-accidental injury.

References:

1. Royal Australian College of General Practitioners (RACGP). “Bruising and bleeding in children: when to worry.”

2. Child Protection Australia. “Identifying normal versus suspicious bruising in infants and toddlers.”

3. Therapeutic Guidelines: Paediatrics (current edition).

4. Medical Journal of Australia. “Bruising in children: Differentiating normal from abnormal.”

5. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.).

6. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

7. Australian Society of Haematology—“Diagnostic approach to suspected bleeding disorders in children.”

Correct Answer: A. Pityriasis rosea ✅

Detailed Explanation:
Pityriasis rosea is the most likely diagnosis given this scenario. It classically begins with a “herald patch”—a single, larger, round/oval lesion with a collarette of scale, presenting days to a week before a secondary eruption of multiple, similar, but smaller oval patches. The distribution typically involves the trunk and proximal limbs, aligning along skin tension lines (so-called “Christmas tree” distribution). The absence of systemic symptoms, absence of fever, and the self-limiting, slightly itchy nature are also characteristic. Pityriasis rosea is common in children and adolescents and is often misdiagnosed initially as allergy or fungal infection.

• B. Tinea corporis: ❌ Tinea typically produces round, annular, scaly plaques with central clearing, often singular or very few in number, not this widespread pattern or the preceding herald patch.

• C. Psoriasis: ❌ While psoriasis may produce well-demarcated, red, scaly plaques, chronicity, typical elbow/knee predilection, and absence of a herald patch or Christmas-tree pattern make this unlikely.

• D. Eczema: ❌ Atopic dermatitis is less common in children without history or family history of atopy, typically involves flexural surfaces, and is usually chronic, excoriated, and intensely pruritic.

• E. Drug eruption: ❌ Drug-induced rashes are often more polymorphic, symmetrical, and involve the face or mucosa; no medication change preceded the rash.

• F. Guttate psoriasis: ❌ Presents after a strep infection with drop-like scaly papules but without a herald patch or scale collarette.

• G. Viral exanthem: ❌ Viral exanthems may appear after systemic symptoms (fever, malaise, URTI), none of which are present here.

Australian guidelines (RACGP, Therapeutic Guidelines: Dermatology, GP Institutes Fellowship AKT KFP guide) recommend that pityriasis rosea be diagnosed clinically in children with the classic pattern, and parents reassured that it is benign and self-limiting, resolving over 6–12 weeks. Antihistamines and emollients may provide symptomatic relief; rarely is further testing or referral needed unless atypical features or persistence prompts reconsideration.

References:

1. Royal Australian College of General Practitioners (RACGP). “The itchy child: Pityriasis rosea in general practice.”

2. Therapeutic Guidelines: Dermatology (current edition).

3. Medical Journal of Australia. “Pityriasis rosea: Clinical diagnosis and management in children.”

4. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.).

5. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

6. Australasian College of Dermatologists. “Clinical Practice Guideline for Diagnosis and Management of Paediatric Rash.”

7. Australian Prescriber. “Diagnosis and management of rashes in children.”

Correct Answer: A. Start potent topical corticosteroids and arrange for regular follow-up ✅

Detailed Explanation:
The classic presentation—intense vulvar itching, burning, dryness, and white skin patches in a postmenopausal woman—suggests lichen sclerosus, a chronic inflammatory dermatosis that predominantly affects the anogenital region of older women. Lichen sclerosus is associated with a significant increased lifetime risk (up to 5%) of vulvar squamous cell carcinoma, and may have a genetic predisposition. The optimal initial management, as per Australian guidelines (RACGP, Therapeutic Guidelines: Dermatology, and the GP Institutes Fellowship AKT KFP guide), is the prompt institution of potent topical corticosteroids (such as clobetasol propionate 0.05% ointment), with clear education on correct use and close follow-up every 3–6 months to monitor treatment response and detect any malignant transformation early. Lifelong surveillance is usually required due to the risk of recurrence and malignancy.

• A. Potent topical corticosteroids plus regular follow-up: The clear first-line treatment for lichen sclerosus, supported by strong evidence for efficacy and safety. Regular review allows ongoing education and early detection of cancerous changes.

Other choices:

• B. Topical oestrogen for atrophic vaginitis ❌ This can address postmenopausal vulvar atrophy/dryness but is not effective for lichen sclerosus and delays appropriate therapy.

• C. Over-the-counter antifungal ❌ Chronic candidiasis is possible but less likely given the examination findings, history, and chronicity; this approach delays correct management.

• D. Moisturisers alone and review in 6 months ❌ Supportive, but grossly inadequate as monotherapy—risks progression, scarring, and missed malignancy.

• E. Immediate biopsy ❌ Biopsy is indicated for lesions suspicious for malignancy (e.g., ulcers, masses, unresponsive areas), but initial trial of corticosteroids and close monitoring is standard when malignancy is not immediately suspected.

• F. Urgent gynaecology referral ❌ Not required unless the diagnosis is uncertain, there is treatment resistance, or cancer is suspected.

• G. Topical tacrolimus ❌ Not first line—may be used in specialist care for refractory cases or allergies to corticosteroids.

Summary:
Lichen sclerosus must be managed with a potent topical corticosteroid and regular follow-up for early detection of complications or malignancy. Timely intervention minimises discomfort, prevents architectural changes, and reduces long-term oncogenic risk.

References:

1. Royal Australian College of General Practitioners (RACGP). Guidelines for the management of vulvar dermatoses and lichen sclerosus.

2. Therapeutic Guidelines: Dermatology (current edition).

3. Cancer Council Australia: Vulvar cancer and pre-malignant vulvar dermatoses.

4. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.).

5. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

6. Australasian College of Dermatologists. “Diagnosis and Management of Lichen Sclerosus.”

7. Medical Journal of Australia. “Vulvar lichen sclerosus: Diagnosis and practical management.”

Correct Answer: A. Discontinue the irritant and use topical corticosteroids ✅

Detailed Explanation:
Emma’s new-onset, well-demarcated, itchy, eczematous rash on extensor surfaces—appearing after changing laundry detergent—is most consistent with allergic contact dermatitis. This is a type IV hypersensitivity reaction, commonly caused by chemicals such as detergents, fragrances, or preservatives, particularly on areas with frequent friction or contact. Australian guidelines (RACGP, Therapeutic Guidelines Dermatology, and the GP Institutes Fellowship AKT KFP guide) advise immediate cessation of the suspected irritant (i.e. reverting to her previous detergent or using a hypoallergenic option). First-line treatment consists of topical corticosteroids (e.g. moderately potent such as mometasone or betamethasone) applied directly to affected areas to reduce inflammation and itching. Emollients and avoidance of scratching are also recommended.

• B. Dapsone 50mg daily ❌ Oral dapsone is reserved for dermatitis herpetiformis and some blistering disorders, not standard eczematous/contact dermatitis.

• C. Permethrin 5% cream ❌ Used to treat scabies; Emma’s distribution, history, and lack of burrows or nocturnal itching are inconsistent with scabies infestation.

• D. Gluten-free diet ❌ Indicated for dermatitis herpetiformis/coeliac disease, which classically causes grouped vesicles and crusts—not eczematous plaques.

• E. Oral antihistamine ❌ May help control itch temporarily, but does not treat the underlying inflammatory process or remove the causative allergen.

• F. Systemic corticosteroids ❌ Reserved for severe, widespread, or refractory cases when topical therapy fails or is impractical; topical treatment is preferable for localised disease.

• G. Skin biopsy ❌ Only required if diagnosis is uncertain or rash does not respond to standard treatment; Emma’s history and findings are typical.

Key Points for the Australian Context:
GPs should routinely assess for contact allergens/irritants in new-onset adult dermatitis. Patient education about avoiding known or suspected triggers and correct application of topical corticosteroids is crucial to rapid resolution and prevention of chronicity or lichenification.

References:

1. Royal Australian College of General Practitioners (RACGP). “Management of Contact Dermatitis in General Practice.”

2. Therapeutic Guidelines: Dermatology (current edition).

3. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

4. Cancer Council Australia: “Diagnosis and Management of Adult Eczema.”

5. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.).

6. Medical Journal of Australia. “Approach to Chronic and Acute Dermatitis in Adults.”

7. Australasian College of Dermatologists. “Allergic Contact Dermatitis: Clinical Practice Guidelines.”

Correct Answer: A. Apply ice to the bite area and provide analgesics for pain management. ✅

Detailed Explanation:
In Australia, the management of a red-back spider bite with localized symptoms only (pain, erythema, mild swelling, and no systemic features) is conservative. The cornerstone of initial therapy, as recommended by RACGP, the Australian Poisons Information Centre, and state health guidelines, is the application of ice/cold packs to the bite site for pain relief, and the use of oral analgesics such as paracetamol or nonsteroidal anti-inflammatory drugs for symptomatic relief. The response to these measures should be assessed, and most cases resolve without complications.

• Antivenom is reserved for severe cases with persistent, severe pain unresponsive to simple or moderate analgesia, or the development of systemic envenoming (which is uncommon in adults and more likely in young children).

• Antibiotics are not indicated unless there is obvious secondary infection (e.g., cellulitis, abscess), which is rare at presentation following a bite.

• Surgical debridement is not warranted, as necrosis is exceedingly rare in red-back spider bites.

• Pressure immobilisation is NOT recommended for red-back spider bites; it can worsen the pain and is not effective as the venom acts slowly.

• Systemic corticosteroids and urgent specialist referral are inappropriate in the absence of allergic or inflammatory complications.

Other potential diagnoses to consider (if systemic features do arise, or if atypical necrotic changes develop) include infection (cellulitis), allergic reactions, and bites from other spiders or insects. In any case of diagnostic doubt or severe symptoms, discussion with a clinical toxicologist or Poisons Information Centre is recommended.

Australian Context and Guidelines:
Red-back spider bites are common and only rarely require antivenom or hospitalisation. Symptomatic management with ice and analgesia is universally recommended for localized, non-severe presentations, with escalation based on clinical progression.

References:

1. RACGP Guidelines: Spider bites—Assessment and management

2. Clinical Practice Guidelines: Spider Bite – Redback Spider (Royal Children’s Hospital, Melbourne)

3. Queensland Poisons Information Centre: Spider bites

4. Australian Family Physician. Spider bite—the redback spider and its relatives

5. Healthdirect Australia: Spider bites—treatment, symptoms, and first aid

6. ANZCOR First Aid Management of Spider Bite (2025)

7. Red Back Spider Antivenom Product Information, Seqirus

8. St John WA: First Aid for Red-back Spider Bite

9. NSW Health: Snake and Spider Bite Clinical Tool

10. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.)

11. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

The correct answer is- Explain that geographic tongue is benign and not cancerous. Reassuring the patient about the benign nature of geographic tongue can alleviate his concerns. Differential diagnoses include oral candidiasis, tongue cancer, iron deficiency anemia, herpes simplex infection, vitamin B12 deficiency, allergic reactions, and lichen planus.

Correct Answer: C. Otitis externa ✅

Detailed Explanation:
Jenna’s presentation—ear canal pain, intense itching, worsened by pinna or tragus movement, canal debris, and hearing reduction in the context of regular exposure to water and a history of using cotton buds—is most consistent with otitis externa (swimmer’s ear). This condition is an inflammation, often infectious, of the external auditory canal and is common among swimmers and surfers, especially in Australia’s warmer climates. Key features include:

• Gradual onset of pain and itchiness

• Tenderness on movement of the pinna or tragus

• Ear canal inflammation with debris or discharge

• Hearing loss due to swelling or blockage

• Tympanic membrane often obscured by debris

A diagnosis of otitis externa is supported by Australian guidelines (RACGP, Healthdirect, Therapeutic Guidelines, and the GP Institutes Fellowship AKT KFP guide), which stress the importance of patient history (recent aquatic exposure, canal trauma, use of objects in the ear) and characteristic examination findings.

Other options:

• A. Cholesteatoma: ❌ Typically presents with chronic, painless, foul-smelling discharge and progressive hearing loss; rarely acute pain or canal tenderness.

• B. Mastoiditis: ❌ Severe post-auricular pain, fever, swelling behind the ear, and protrusion of the pinna—none seen here.

• D. Otitis media: ❌ Usually presents as deep ear pain, systemic symptoms (fever), and pain unaltered by pinna movement; eardrum is typically visible (unless canal swelling is extreme).

• E. Ruptured tympanic membrane: ❌ May cause sharp pain and sudden discharge, followed by relief—no such acute history, and tympanic membrane is not visualised due to canal swelling.

• F. Surfer’s ear (exostosis): ❌ Benign bone growth causing chronic obstruction, hearing loss, and recurrent infections; not acutely inflamed or tender to auricle movement, but increases the risk of otitis externa.

• G. Acute allergic otitis: ❌ Allergic canal dermatitis can cause itch/comfy, but pronounced pain, inflamed debris, and risk factors support infection.

Summary:
Otitis externa is the most likely diagnosis for Jenna, a young surfer with ear pain, itching, canal debris and pain on pinna movement. Timely recognition prevents progression and complications.

References:

1. RACGP. “Approach to Otitis Externa in Australian General Practice,” AJGP, 2024.

2. Healthdirect Australia. “Swimmer’s ear (otitis externa) – symptoms and treatment,” 2023.

3. Queensland Health. Otitis Externa Clinical Practice Guideline, 2025.

4. Better Health Channel. “Swimmer’s ear,” Victoria Department of Health.

5. Perth Children’s Hospital: Otitis externa – Emergency Department Guidelines.

6. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

7. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.).

8. Therapeutic Guidelines: Ear, Nose & Throat (current edition).

9. Medical Journal of Australia: “Diagnosis and Management of Ear Infections in Adults.”

Correct answer is – MRI of the brain and internal auditory canal. This investigation can help rule out acoustic neuroma and other central causes of sudden sensorineural hearing loss. Tympanometry and pure tone audiometry assess hearing loss but do not identify the underlying cause. A CT scan is less sensitive for soft tissue lesions like neuromas. Blood glucose level is irrelevant to the immediate investigation of hearing loss. Differential diagnoses include acoustic neuroma, labyrinthitis, sudden idiopathic sensorineural hearing loss, vascular events, and multiple sclerosis.

The correct answer is- Acute pancreatitis. The combination of epigastric pain radiating to the back and elevated lipase levels is indicative of acute pancreatitis, commonly associated with alcohol use. Differential diagnoses include peptic ulcer disease, gallstones, gastritis, hepatitis, myocardial infarction, esophageal spasm, and biliary colic.

The correct answer is- Refer urgently to a hematologist. The presence of anemia, lymphadenopathy, and weight loss warrants urgent referral for further investigation. Differential diagnoses include infectious mononucleosis, iron deficiency anemia, depression, substance abuse, chronic fatigue syndrome, tuberculosis, and non-Hodgkin’s lymphoma.

Answer: D. Arrange for urgent surgical consultation for suspected acute appendicitis. ✅

Detailed Explanation:

1. Arrange for urgent surgical consultation for suspected acute appendicitis. ✅ The most appropriate next step in managing Eleanor’s condition is to arrange for urgent surgical consultation for suspected acute appendicitis. Eleanor presents with classic symptoms and signs of acute appendicitis: acute onset of periumbilical pain migrating to the right lower quadrant (RLQ), constant and worsening pain, associated nausea and vomiting, and fever ($38.2^\\circ\\text{C}$). Physical examination reveals marked RLQ tenderness with rebound and guarding, and a positive Rovsing’s sign, all indicative of peritoneal irritation due to appendiceal inflammation. Her negative urine beta-hCG rules out ectopic pregnancy (a key differential). Given the high clinical suspicion for acute appendicitis, which is a surgical emergency due to the risk of perforation, urgent surgical consultation (with a general surgeon) is paramount for definitive diagnosis and treatment. This allows for rapid assessment and planning for appendicectomy, which is the definitive treatment.
2. Order a pelvic ultrasound immediately. ❌ While a pelvic ultrasound is important for evaluating gynaecological causes of RLQ pain (e.g., ovarian torsion, ruptured ovarian cyst, PID) in a sexually active woman, it is not the most appropriate immediate next step when the clinical picture is classic for acute appendicitis. Her negative urine beta-hCG has already ruled out ectopic pregnancy, and her symptoms (migratory pain, fever, clear peritoneal signs) are more typical of appendicitis than gynaecological pathology. Although a pelvic ultrasound might be done in some settings as part of a broader workup, the immediate priority for suspected appendicitis is surgical consultation. Abdominal CT scan is often preferred for appendicitis confirmation.
3. Initiate empiric broad-spectrum antibiotics for suspected pelvic inflammatory disease (PID). ❌ Initiating empiric broad-spectrum antibiotics for suspected PID is inappropriate as the initial management step. While PID can cause lower abdominal pain in sexually active women, the classic symptoms of PID include bilateral lower abdominal pain, often with cervical motion tenderness (CMT) and vaginal discharge. Eleanor’s pain is primarily unilateral (RLQ), and she has no CMT or purulent discharge. More importantly, her presentation with migratory pain, marked RLQ guarding/rebound, and positive Rovsing’s sign strongly suggests an acute surgical abdomen (appendicitis), not primarily PID, which is typically managed medically.
4. Administer analgesia and observe for 4-6 hours. ❌ Administering analgesia is appropriate for pain relief, but simply observing for 4-6 hours is dangerously negligent for suspected acute appendicitis. Acute appendicitis is a surgical emergency. Delaying definitive diagnosis and surgical intervention increases the risk of appendiceal perforation, peritonitis, abscess formation, and sepsis, leading to significantly higher morbidity and mortality. She needs urgent surgical assessment, not observation.
5. Perform a serum lactate dehydrogenase (LDH) and C-reactive protein (CRP) test. ❌ Performing serum LDH and CRP tests would confirm systemic inflammation (CRP would be elevated, LDH is non-specific). However, these are non-specific inflammatory markers and would not differentiate appendicitis from other inflammatory or infectious causes. The clinical presentation is already highly suggestive of appendicitis, and the priority is definitive diagnosis and treatment, not just confirmation of inflammation. These tests would be part of a broader lab workup, but not the determining next step.
6. Schedule an exploratory laparotomy. ❌ Scheduling an exploratory laparotomy (open abdominal surgery) is the definitive surgical treatment for acute appendicitis. However, it is not the immediate next step after clinical suspicion. The proper next step is to arrange for urgent surgical consultation (Option D). The surgeon will then decide whether to proceed directly to the operating theatre based on the clinical picture, or whether further imaging (e.g., CT scan of the abdomen) is required for confirmation or to rule out other diagnoses before surgery.
7. Discharge home with advice to return if symptoms worsen. ❌ Discharging Eleanor home with advice to return if symptoms worsen is grossly negligent and unacceptable. She is acutely unwell with severe abdominal pain, peritoneal signs, fever, and tachycardia, strongly indicating an acute surgical emergency (appendicitis). Discharging her would put her at extreme risk of perforation, sepsis, and severe complications. She requires immediate hospitalisation and surgical assessment.

References:

• RACGP Source: Gold, J., & Backhouse, K. (2019). Acute abdominal pain: An approach for general practitioners. Australian Family Physician, 48(12), 850-854. https://www1.racgp.org.au/ajgp/2019/december/acute-abdominal-pain
• Therapeutic Guidelines: Therapeutic Guidelines. (2024). Therapeutic Guidelines: Surgery (eTG). North Melbourne, Vic: Therapeutic Guidelines Limited. (Specifically, sections on Acute Appendicitis: Diagnosis and Management).
• Murtagh’s: Murtagh, J., & Murtagh, J. E. (2022). Murtagh’s General Practice (8th ed.). McGraw-Hill Education (Australia) Pty Ltd. (General Surgery; specifically on Acute Appendicitis).
• Royal Australasian College of Surgeons (RACS): RACS. (2019). Acute Appendicitis: Clinical Guidelines. (Provides Australian clinical guidelines for the management of acute appendicitis). [Relevant sections are usually found in RACS publications or major hospital guidelines based on RACS advice].
• Life in the Fast Lane: Life in the Fast Lane. (2024). Acute Appendicitis. https://litfl.com/acute-appendicitis/
• GP Institutes Fellowship AKT KFP guide textbook: GP Institute of Australia (2025). FRACGP AKT & KFP Exam Preparation Guide (1st ed.). Sydney, Australia: Aumyania Pty Limited. (Relevant sections on acute abdomen and surgical emergencies).
• Royal Children’s Hospital Melbourne: Royal Children’s Hospital Melbourne. (2023). Abdominal Pain (Acute). https://www.rch.org.au/clinicalguide/guideline_index/Abdominal_pain_acute/ (Provides context for paediatric abdominal pain, though patient is adult, principles similar).

The Red Book promotes evidence-based medicine, ensuring that recommended interventions offer clear benefits for specific populations. Screening tests without proven benefit are not recommended to avoid potential risks.

Correct Answer: B. To manage symptoms and modify disease course ✅

Detailed Explanation:
Methotrexate is the first-line disease-modifying antirheumatic drug (DMARD) prescribed for rheumatoid arthritis (RA) in Australia, in accordance with RACGP, Therapeutic Guidelines, and the GP Institutes Fellowship AKT KFP guide. Its primary rationale is to reduce joint inflammation, prevent long-term structural damage, improve function, and modulate the disease course—not just to relieve pain. Early use of methotrexate can slow or halt disease progression, lower rates of disability, and improve long-term outcomes.

Folic acid is always co-prescribed with methotrexate because methotrexate inhibits dihydrofolate reductase, interfering with folate metabolism and leading to side effects like oral ulcers, gastrointestinal distress, liver enzyme elevation, and cytopenias. Supplementing with folic acid reduces the risk and severity of these side effects but does not diminish methotrexate’s efficacy.

• A. To address possible vitamin deficiencies: ❌ While folic acid is a vitamin, the rationale for supplementation is specifically to reduce the toxicity of methotrexate, not to treat pre-existing vitamin deficiency.

• C. Immediate pain relief: ❌ Methotrexate does not provide rapid symptom relief; NSAIDs or corticosteroids are typically used initially for acute symptom control.

• D. Prevent iron deficiency complications: ❌ Methotrexate and folic acid do not affect iron metabolism or iron-deficiency anemia.

• E. Treat secondary infections: ❌ Neither agent treats infections; methotrexate can even increase infection risk due to immunosuppression.

• F. Improve sleep quality in chronic pain: ❌ While improved disease control may secondarily help sleep, this is not the primary rationale for DMARD initiation.

• G. Reverse established joint deformity: ❌ Methotrexate and DMARDs slow further deformity but cannot reverse structural joint changes once established.

Australian guidelines strongly advocate early DMARD initiation—especially with methotrexate—for anyone meeting criteria for RA to optimise long-term quality of life and functional independence. Folic acid co-prescription is standard to ensure safety and adherence.

References:

1. Royal Australian College of General Practitioners (RACGP). “Management of rheumatoid arthritis in general practice,” Guidelines.

2. Therapeutic Guidelines: Rheumatology (current edition).

3. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.).

4. Australian Rheumatology Association: Algorithms for the use of DMARDs.

5. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

6. Arthritis Australia: Methotrexate patient information and safety.

7. Medical Journal of Australia. “Current perspectives on methotrexate use in RA.”

Correct Answer: B. Suggests a non-specific inflammatory response ✅

Detailed Explanation:
A mildly elevated ESR in Michelle’s context indicates a non-specific inflammatory response, supporting the presence of an underlying inflammatory process such as rheumatoid arthritis (RA). ESR (erythrocyte sedimentation rate) is a sensitive but non-specific marker of systemic inflammation, influenced by various factors including age, chronic conditions, and acute illness. In RA, an elevated ESR is often seen and can reflect disease activity but is not diagnostic or solely specific for RA. In Michelle’s case, her clinical features, anti-CCP positivity (highly specific for RA), and chronic, symmetric small joint involvement further support the diagnosis of seronegative (RF-negative) rheumatoid arthritis.

Australian guidelines (RACGP, Therapeutic Guidelines, GP Institutes Fellowship AKT KFP guide) emphasise that ESR must always be interpreted in conjunction with the clinical picture, antibody testing, and imaging. While a raised ESR supports inflammation, it cannot specify etiology or confirm diagnosis alone.

Other answers explained:

• A. Indicates significant joint damage ❌ ESR may be raised without evident structural damage; joint damage is best assessed radiographically.

• C. Confirms SLE ❌ While ESR may be raised in SLE, it is not diagnostic and Michelle’s clinical picture lacks lupus features.

• D. Rules out RA ❌ Most RA patients have raised ESR, but a normal ESR does not exclude RA; diagnosis relies primarily on clinical criteria and serology.

• E. Points to need for cancer evaluation ❌ ESR may be raised in cancer, but in this scenario, the history and findings point to inflammatory arthritis.

• F. Demonstrates acute bacterial infection ❌ Infection would likely have a higher ESR and systemic features (fever, raised WBC).

• G. Medication-induced inflammation ❌ Michelle has not used chronic or new medications that could cause elevated ESR.

Summary:
A mildly elevated ESR reflects an underlying non-specific inflammatory response in a patient with inflammatory arthritis but does not confirm or exclude a diagnosis. It must be interpreted as part of a holistic assessment, guiding decisions about disease activity and monitoring over time.

References:

1. Royal Australian College of General Practitioners (RACGP). “Approach to the patient with joint pain and elevated inflammatory markers.”

2. Therapeutic Guidelines: Rheumatology (current edition).

3. GP Institute of Australia. FRACGP AKT & KFP Exam Preparation Guide (1st ed.).

4. Australian Rheumatology Association: Guidelines for the management of early rheumatoid arthritis.

5. Murtagh J. Murtagh’s General Practice (8th ed.), McGraw-Hill Education (Australia) Pty Ltd.

6. Medical Journal of Australia. “Seronegative rheumatoid arthritis: Clinical assessment and diagnosis.”

7. Cancer Council Australia: “Interpreting elevated ESR—when to worry?”

Topical estrogen therapy is the most appropriate initial management for postmenopausal women experiencing dyspareunia due to vaginal atrophy. Referral to a pelvic pain specialist may be needed if symptoms persist. Cognitive-behavioral therapy is more appropriate for psychological factors. Vaginal dilators and pelvic floor physical therapy may be considered if topical estrogen therapy fails, but are not first-line treatments. Differential diagnoses include vaginal atrophy, vulvovaginal atrophy, lichen planus, endometriosis, pelvic inflammatory disease, vestibulodynia, and vulvodynia.

Polycystic ovary syndrome (PCOS) is the most likely cause given Maria’s irregular menstrual cycles and hirsutism. Tubal obstruction is less likely with normal semen analysis. Hyperprolactinemia usually presents with additional symptoms. Endometriosis often has different symptoms. Uterine fibroids would present with other symptoms. Differential diagnoses include PCOS, hypothyroidism, ovarian insufficiency, early menopause, chronic anovulation, adrenal hyperplasia, and stress-related infertility.

Correct answer: Order serological tests for tick-borne diseases
Given Mia’s symptoms and travel history, Lyme disease should be considered. Serological tests can confirm tick-borne diseases like Lyme disease, which may present with a rash, fever, and joint pain.

Incorrect answers:
❌ Start oral antihistamines – Antihistamines are not appropriate for suspected tick-borne diseases like Lyme disease.
❌ Administer intravenous antibiotics – Antibiotics should be considered only after confirming a diagnosis, not as the first step.
❌ Provide supportive care and monitor – While supportive care is important, it does not address the potential underlying infectious cause.
❌ Initiate corticosteroid therapy – Steroids may be necessary for certain conditions but should not be started without a confirmed diagnosis.

Learning Objective:
To recognize tick-borne diseases in travelers and understand the role of serological testing in diagnosis.. Differential diagnoses include: 1) Lyme disease, 2) Rocky Mountain spotted fever, 3) Viral exanthem, 4) Juvenile idiopathic arthritis, 5) Rheumatic fever, 6) Parvovirus infection, 7) Systemic lupus erythematosus. A – Antihistamines are not indicated for suspected tick-borne disease. B – Antibiotics may be needed but should follow confirmation of diagnosis. D – Supportive care is important but does not address the underlying cause. E – Steroids may be used in certain conditions but not as an initial step without diagnosis.

The most appropriate management is urgent laparoscopy due to the presence of circulatory collapse and severe pain, indicating a possible ruptured ectopic pregnancy. Differential diagnoses include: 1. Ectopic pregnancy, 2. Ovarian torsion, 3. Acute appendicitis, 4. PID, 5. Ovarian cyst rupture, 6. Endometriosis, 7. Gastrointestinal perforation.

The correct answer is- Sarcoidosis is compatible with a long and active life. Most patients with sarcoidosis have a good prognosis and can lead normal lives, although some may require intermittent treatment. Differential diagnoses include tuberculosis, Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, granulomatosis with polyangiitis, systemic lupus erythematosus, thyroid cancer, and metastatic breast cancer.

The appropriate management step for retinal detachment is immediate referral for sealing of retinal tears. The symptoms suggest retinal detachment, which requires urgent surgical intervention. Differential diagnoses include vitreous haemorrhage, central retinal artery occlusion, and central retinal vein thrombosis.

The most appropriate initial treatment for a confirmed DVT is to start low molecular weight heparin (LMWH), such as enoxaparin, to prevent further clot formation and embolization. Differential diagnoses include cellulitis, Baker’s cyst, muscle strain, venous insufficiency, lymphedema, and superficial thrombophlebitis. Oral aspirin is not effective for treating DVT. Thrombolytic therapy is reserved for massive DVT with severe symptoms. Warfarin is typically started after LMWH, not immediately. Compression stockings are supportive but not a primary treatment.

The most appropriate management involves prescribing analgesics and encouraging deep breathing to prevent complications such as pneumonia. Differential diagnoses include: rib fracture, pneumothorax, lung contusion, splenic injury, hepatic injury, kidney trauma, and intercostal muscle strain. Elastic rib belts or surgical interventions are less supported by evidence or unnecessary for simple fractures.

The correct answer is- Abstain from sexual activity during outbreaks. Avoiding sexual contact during active outbreaks reduces the risk of transmission to partners. Differential diagnoses include syphilis, gonorrhea, chlamydia, balanitis, chancroid, fixed drug eruption, and Behçet’s disease.

Referral for adenotonsillectomy is the most appropriate management for a child with obstructive sleep apnea due to enlarged tonsils. Differential diagnoses include: 1) Allergic rhinitis 2) Asthma 3) Attention deficit hyperactivity disorder 4) Gastroesophageal reflux disease 5) Obesity 6) Craniofacial abnormalities 7) Neuromuscular disorders

The correct answer is- Chromosomal abnormalities. Early miscarriages are often due to isolated chromosomal abnormalities, which are usually not recurrent. Differential diagnoses include uterine abnormalities, hormonal imbalance, infection, immunological disorders, cervical incompetence, lifestyle factors, and thrombophilia.

Obesity is a major risk factor for a number of chronic diseases, including type 2 diabetes, heart disease, stroke, and sleep apnea. It is important to address obesity early to reduce the risk of these complications.

The correct answer is- Non-maleficence (do no harm). The GP must ensure that any action taken does not intentionally harm the patient, such as administering a medication with the intent to hasten death. Differential diagnoses include ethical dilemmas in palliative care, end-of-life care issues, anxiety in family members, misunderstanding of medical processes, potential elder abuse, depression in family members, and caregiver fatigue.

The correct answer is- Polymyalgia rheumatica (PMR). The age of the patient, sudden onset of stiffness, and prolonged morning stiffness are characteristic of PMR. Other conditions like rheumatoid arthritis and fibromyalgia have different clinical presentations. Differential diagnoses include rheumatoid arthritis, osteoarthritis, fibromyalgia, depression, multiple myeloma, temporal arteritis, and hypothyroidism.

Blood glucose level, urine analysis, and HbA1c are necessary to confirm the diagnosis of type 1 diabetes mellitus. Thyroid function tests can help to rule out hyperthyroidism as a possible cause of the patient’s symptoms.

The correct answer is- Corneal light reflex test. The corneal light reflex test helps assess eye alignment by observing the reflection of light on the corneas. Differential diagnoses include congenital esotropia, intermittent exotropia, pseudostrabismus, refractive error, retinoblastoma, cataract, and neurological disorder.

The likely diagnosis is dry macular degeneration . It presents with gradual loss of central vision and distortion of vision. Differential diagnoses include wet macular degeneration, retinal detachment, central retinal artery occlusion, and vitreous haemorrhage.

The correct answer is- Malabsorption due to Coeliac disease. Coeliac disease can cause malabsorption, leading to iron deficiency anemia and fatigue. Noncompliance with a gluten-free diet could contribute, but malabsorption is the direct cause. Differential diagnoses include iron deficiency anemia, vitamin B12 deficiency, folate deficiency, inflammatory bowel disease, small intestinal bacterial overgrowth, chronic gastrointestinal bleeding, and thyroid dysfunction.

The patient’s presentation, including persistent lymphadenopathy and elevated lymphocytes, with a blood film showing sparse cytoplasm, is indicative of Chronic Lymphocytic Leukaemia (CLL). This condition is common in older adults and often presents with lymphadenopathy and elevated lymphocytes. Acute lymphoblastic leukaemia and other conditions like infectious mononucleosis or myeloma have different clinical and laboratory features.

Correct answer is to refer to a hepatologist for further assessment and potential antiviral therapy. Differential diagnoses include autoimmune hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease, hemochromatosis, Wilson’s disease, alpha-1 antitrypsin deficiency, and drug-induced liver injury. Vaccination is inappropriate in an already infected patient; antivirals might be necessary but require specialist input; lifestyle modifications alone are insufficient; liver biopsy may be considered after hepatology consultation.

Endoscopy is useful for assessing oesophageal causes of chest pain, such as GERD. An exercise stress test and transthoracic echocardiography are more relevant for cardiac causes. Serum enzymes and chest X-ray do not directly assess oesophageal conditions. Endoscopy allows direct visualization of the esophagus and can identify inflammation or structural abnormalities.

Transoesophageal echocardiography (TOE) is the most sensitive investigation for aortic dissection. A chest X-ray and transthoracic echocardiography are useful but less sensitive. An exercise stress test and serum enzymes are not relevant for diagnosing aortic dissection. TOE provides detailed images of the aorta and can quickly confirm the presence of a dissection.

An exercise stress test is most appropriate to define the cardiac origin of chest pain during exercise. A chest X-ray and transthoracic echocardiography are useful but do not specifically assess exercise-induced ischemia. Blood glucose and haemoglobin tests are not directly related to diagnosing cardiac chest pain. The exercise stress test evaluates for myocardial ischemia by assessing ECG changes during physical exertion.

Retained tampons can cause persistent discharge and irritation. Removing the tampon and managing any resultant infection or irritation is crucial. Differential diagnoses include: 1. Retained foreign objects (e.g., tampons), 2. Bacterial vaginosis, 3. Candida albicans, 4. Atrophic vaginitis, 5. Contact dermatitis, 6. Diabetes-related infections, 7. Vulvar malignancies.

Correct answer: Repeat the blood test to confirm the results

Tips for AKT/KFP Candidates:

• Chronic kidney disease requires persistent eGFR reduction (<60 mL/min) for at least three months for diagnosis. Acute illness, dehydration, recent medications, laboratory error, or calculation issues (including lack of ethnicity adjustment) can cause transient or spurious reductions.

• Always repeat serum creatinine and eGFR (and ACR if not already done) within 1–2 weeks before making a new CKD diagnosis or referral, especially if results were previously normal.

• eGFR calculations may underestimate kidney function in patients of African or Afro-Caribbean descent if not adjusted; confirm if lab has included ethnic factor. Age also affects eGFR.

• Immediate specialist referral is reserved for patients with eGFR <30, rapid decline, proteinuria, or other red flags. For newly identified isolated eGFR 45–59 (stage 3A), repeat and confirm persistent abnormality before referring.

• Continue regular antihypertensive therapy and lifestyle modification—no need to start new antihypertensives if BP is at target.

• Counsel the patient about the preliminary findings, next steps, and the importance of hydration and medication adherence. Review all medications for nephrotoxic agents.

• Follow RACGP Red Book, Therapeutic Guidelines: Nephrology, Kidney Health Australia, and the GP Institute Fellowship AKT/KFP Guidebook recommendations for CKD assessment and referral.

Detailed Explanation

Why “Repeat the blood test to confirm the results” is correct:
CKD cannot be diagnosed from a single test, particularly if previous kidney function was normal or nearly normal, or if there are factors (ethnicity, age, recent illness) that might influence the result. Confirmation with repeat testing (at least three months apart if diagnosis is unclear) is required by Australian guidelines before referral or formal disease labelling, which may affect insurance or patient welfare long term.

Why other answers are less suitable:
A. Nephrology referral is not indicated until eGFR decline is persistent and meets criteria; unnecessary for a single, borderline result.
C. Monitoring without confirmation risks missing reversible causes and misclassifying CKD.
D. Additional antihypertensives are not needed with controlled blood pressure.
E. No action disregards a potentially serious abnormal result.

References:

1. RACGP Red Book: Chronic kidney disease—screening and investigation (2023)

2. Therapeutic Guidelines: Nephrology—CKD diagnosis and monitoring

3. Kidney Health Australia—CKD eGFR protocols

4. GP Institute Fellowship AKT/KFP Guidebook—CKD diagnosis and referral guidelines

5. Australasian Creatinine Consensus Group: eGFR interpretation (2024)

Patient education is crucial in the management of BPH. The patient should be informed about the importance of regular follow-up appointments, lifestyle modifications to improve symptoms, the potential complications of BPH, and the importance of seeking medical attention for worsening symptoms.

Rheumatic fever is associated with a history of untreated sore throats, fever, joint pain, and rash. Differential diagnoses include systemic lupus erythematosus, infective endocarditis, viral exanthema, reactive arthritis, rheumatoid arthritis, and Kawasaki disease. A is incorrect as systemic lupus erythematosus would have additional systemic involvement. B is incorrect as infective endocarditis would present with a history of intravenous drug use or prosthetic valves. C is incorrect as viral exanthema would not cause joint pain. E is incorrect as reactive arthritis follows gastrointestinal or genitourinary infections.

Diabetic Nephropathy (DN)

Diabetic nephropathy (DN) is exceedingly common in patients with both type 1 and type 2 diabetes mellitus and is characterized by persistent albuminuria (>30 mg/g) and/or decreased glomerular filtration rate (GFR) (e.g., elevated creatinine). DN is typically slowly progressive for years before clinical signs occur.

The diagnosis is usually made clinically, with renal biopsy reserved for patients with an unclear presentation. In the absence of signs suggesting another etiology (e.g., casts in the urine, rapid progression of renal dysfunction), the diagnosis can be presumed in patients who have persistent albuminuria and/or decreased GFR and either of the following:

• Prolonged history of diabetes:

  • Type 1 diabetes is typically clinically obvious at onset; therefore, DN may be assumed in those with a disease duration of ≥5 years.
  • In contrast, type 2 diabetes is often asymptomatic, so patients may have this disorder for years before diagnosis, making the duration of the disease difficult to calculate.

• Proliferative Diabetic Retinopathy (PDR):

  • Both PDR (i.e., retinal neovascularization) and DN are chronic microvascular complications of diabetes due to persistent hyperglycemia, so the presence of PDR correlates with diabetic kidney disease.
  • Therefore, patients may be diagnosed with DN if there is concomitant PDR, regardless of the length of time since diagnosis.

Differential Diagnoses

• (Choice A) Renal Size Discrepancy

  • Seen in patients with unilateral chronic kidney disease (e.g., renal artery stenosis, ureteral obstruction).
  • With prolonged DN, both kidneys would likely be shrunken and atrophic.

• (Choice B) Left Ventricular Hypertrophy (LVH)

  • Correlates with chronic, uncontrolled hypertension.
  • Although uncontrolled hypertension may be seen in patients with chronic kidney disease, it is not specific for DN.

• (Choice C) Microscopic Hematuria

  • Although microscopic hematuria may occur with DN, it is nonspecific and may be seen in a variety of diseases (e.g., malignancy, nephritic syndromes).

• (Choice D) Rapidly Progressive Renal Dysfunction

  • DN usually develops over a prolonged period (years).
  • Rapidly progressive renal dysfunction suggests an alternate diagnosis (e.g., lupus nephritis) and further workup.
  • Renal biopsy may be indicated.

Learning Objective

Diabetic nephropathy (DN) is characterized by persistent albuminuria (>30 mg/g) and/or decreased glomerular filtration rate. In the absence of signs suggestive of another etiology, the diagnosis can be presumed in patients with renal dysfunction and either:

• A prolonged history of diabetes (≥5 years for type 1 diabetes)
• Proliferative diabetic retinopathy, which correlates with the presence of DN

Type 2 Diabetes in Adolescents and Young Adults

This patient with a new diagnosis of diabetes mellitus (elevated hemoglobin A1c level, symptomatic hyperglycemia [e.g., polydipsia], vulvovaginal candidiasis) likely has type 2 diabetes. Although type 2 diabetes is more common in older individuals, the incidence in adolescents and young adults is increasing in association with a rise in childhood obesity (e.g., BMI ≥95th percentile for age).

Excess adiposity contributes to insulin resistance, which is further aggravated by rising growth hormone levels at puberty. A positive family history of diabetes increases the risk; the incidence is also higher in certain racial and ethnic groups (e.g., Black and Native American patients).

Associated Features of Insulin Resistance

• Central (visceral) obesity
• Elevated blood pressure
• Lipid abnormalities (e.g., hypertriglyceridemia, decreased HDL levels)
• Acanthosis nigricans: Velvety, hyperpigmented patches in intertriginous areas (e.g., neck, axillae)

Differential Diagnoses

• (Choice A) Growth Hormone-Secreting Pituitary Adenoma

  • Can cause diabetes mellitus
  • Bitemporal hemianopia may occur due to optic chiasm compression
  • However, patients typically display gigantism or acromegaly rather than obesity

• (Choice B) Chronic Pancreatitis

  • Can lead to exocrine pancreatic insufficiency → steatorrhea
  • Loss of beta cells can cause secondary diabetes
  • However, this is much more common at age >30 and is typically associated with:
    • Chronic abdominal pain
    • Nausea
    • Weight loss

• (Choice D) Glucokinase Gene Mutation (MODY – Maturity-Onset Diabetes of the Young)

  • Characterized by decreased insulin secretion at any glucose level
  • Patients are typically not obese
  • Hyperglycemia is usually mild (<140 mg/dL)

• (Choice E) Autoimmune Type 1 Diabetes

  • Pancreatic autoantibodies cause loss of islet cells
  • Leads to absolute insulin deficiency (vs. relative deficiency in type 2 diabetes)
  • Increased ketone production can lead to diabetic ketoacidosis (DKA)
  • Typical features include:
    • Rapid-onset hyperglycemia
    • Ketonuria (absent in this patient)
    • Hyperventilation
    • Abdominal pain

Learning Objective

The incidence of type 2 diabetes in adolescents and young adults is increasing due to rising childhood obesity. Excess adiposity contributes to insulin resistance, which is further aggravated by pubertal growth hormone levels. Other findings associated with insulin resistance include acanthosis nigricans, central obesity, hypertension, and lipid abnormalities.

Hyperprolactinemia Due to Antipsychotic Use

This patient’s history of paranoia, social isolation, and disorganized behavior suggests psychosis, likely being treated with an antipsychotic medication. Antipsychotic drugs block dopamine, and since dopamine inhibits prolactin release, dopamine blockade in the tuberoinfundibular pathway can lead to hyperprolactinemia. This can result in gynecomastia, galactorrhea, menstrual dysfunction, and decreased libido.

Risperidone, a commonly used second-generation antipsychotic (SGA), is known for its high frequency of prolactin elevation and is the most likely cause of this patient’s symptoms.

Differential Diagnoses

• (Choice A) Aripiprazole

  • Functions as a dopamine D2 receptor antagonist and partial agonist
  • Due to its partial agonism, it is less likely to cause hyperprolactinemia

• (Choice B) Galactocele

  • A benign milk collection in lactating women, usually due to a blocked duct
  • This patient’s pregnancy test is negative, and there is no indication of breastfeeding

• (Choice C) Hypothyroidism

  • Can predispose to hyperprolactinemia, but typically presents with:
    • Lethargy
    • Dry skin
    • Cold intolerance
  • This patient has none of these symptoms, and her TSH level is normal

• (Choice D) Polycystic Ovary Syndrome (PCOS)

  • Associated with elevated androgens, leading to:
    • Acne
    • Hirsutism
    • Menstrual irregularities
  • Can occasionally cause elevated prolactin levels, but this patient lacks symptoms of hyperandrogenism

• (Choice E) Prolactinoma

  • A benign pituitary tumor causing:
    • Headaches
    • Visual disturbances (due to mass effect)
  • Can lead to extremely high prolactin levels (>200 ng/ml)
  • In contrast, medication-induced hyperprolactinemia typically results in prolactin levels between 25-100 ng/ml

• (Choice G) Valproate

  • An anticonvulsant used for:
    • Bipolar disorder
    • Seizures
  • Does not cause galactorrhea, but is associated with:
    • Blood dyscrasias
    • Liver toxicity

Learning Objective

Antipsychotic medications can cause hyperprolactinemia due to dopamine blockade in the tuberoinfundibular pathway. Risperidone has a particularly high risk of prolactin elevation. In contrast, prolactinomas typically produce very high prolactin levels (>200 ng/ml), whereas antipsychotic-induced hyperprolactinemia generally results in levels between 25-100 ng/ml.

Short Stature and Constitutional Growth Delay

This patient has short stature, defined as height below the 2nd percentile for sex and age. The most common causes of short stature are constitutional growth delay and familial short stature.

Constitutional Growth Delay

• Recognized by a delayed bone age and a normal linear growth velocity starting around age 3
• Affected children typically have a normal birth weight and height but exhibit slowed linear growth velocity between 6 months and 3 years, leading to a height below the 2nd percentile
• After age 3, growth resumes at a normal rate (ie, normal growth velocity), with the growth curve remaining below but parallel to the lowest percentile line
• Delayed puberty, including late adolescent growth spurt
• Bone age (skeletal maturation) is delayed relative to chronological age
• Ultimately, patients experience a normal growth spurt and achieve a normal adult height

Management

• Reassurance and monitoring of linear growth velocity

Differential Diagnoses

• (Choice A) Celiac Disease

  • Can cause short stature and delayed bone age
  • Typically presents with weight loss and gastrointestinal symptoms (eg, diarrhea, abdominal distension)
  • This patient has appropriate weight gain and no gastrointestinal symptoms

• (Choice C) Familial Short Stature

  • Bone age is normal and matches chronologic age
  • Puberty is not delayed
  • Patients have a normal linear growth velocity (stable percentile), similar to constitutional growth delay
  • One or both parents also have short stature (not the case in this patient)
  • Final adult height remains low

• (Choice D) Growth Hormone Deficiency

  • Causes short stature, delayed puberty, and delayed bone age
  • Slowed linear growth velocity, with height percentiles crossing 2 major percentiles downward (eg, from 50th to 25th)
  • This patient’s height percentile is stable, suggesting normal linear growth velocity

• (Choice E) Hypogonadism (Testosterone Deficiency)

  • Can be congenital (eg, Klinefelter syndrome) or acquired (eg, testicular trauma or infection)
  • Delayed puberty, but normal bone age
  • Most patients have gynecomastia, which is not present in this case
  • Often associated with increased LH, FSH, and estradiol due to lack of testosterone’s negative feedback

• (Choice F) Hypothyroidism

  • Causes declining linear growth velocity and pubertal delay
  • This patient’s linear growth velocity is normal
  • No symptoms of hypothyroidism (eg, fatigue, constipation, cold intolerance)

Learning Objective

Constitutional growth delay is characterized by short stature (height below the 2nd percentile), delayed bone age, and a normal linear growth velocity after age 3. Delayed puberty is common, but patients eventually experience a normal growth spurt and achieve a normal adult height.

Nutritional Rickets

Nutritional rickets is most commonly caused by vitamin D deficiency, which is essential for calcium metabolism and skeletal growth. Risk factors include limited sun exposure and increased skin pigmentation. Exclusively breastfed infants who do not receive vitamin D supplementation, as in this case, are at high risk because breast milk alone contains inadequate vitamin D.

Deficiency of vitamin D and calcium results in poor bone mineralization and growth plate cartilage accumulation. Clinical features include:

• Craniotabes (skull bones that depress with pressure), as seen in this infant
• Widened wrists due to growth plate enlargement
• Radial/ulnar bowing
• Delayed fontanel closure
• Lower extremity bowing (genu varum) once the child begins weight-bearing

Diagnosis & Imaging

X-ray of rapidly growing skeletal areas (eg, wrists, knees) is helpful for diagnosis. Classic findings include:

• Metaphyseal widening with cupping and fraying (white arrow), as seen here
• Costochondral joint widening

Treatment

Treatment involves vitamin D and calcium supplementation.

Differential Diagnoses

• (Choice A) Systemic Juvenile Idiopathic Arthritis (JIA)

  • Autoimmune inflammatory disorder
  • Presents with fever, arthritis, and rash (none of which are present here)
  • X-rays show soft tissue swelling and loss of joint space, not metaphyseal changes

• (Choice B) Hurler Syndrome

  • Autosomal recessive lysosomal storage disease
  • Characterized by dysostosis multiplex (shortened, thickened long bones)
  • Other features include coarse facial features (wide nasal bridge, flat midface), developmental delay, and frequent infections, none of which are seen here

• (Choice C) HIV

  • Can be transmitted via breast milk
  • Presents with hepatosplenomegaly, lymphadenopathy, and failure to thrive, rather than bony abnormalities
  • Milk banks screen donors for infectious diseases and pasteurize milk to destroy pathogens, including HIV

• (Choice D) Congenital Syphilis

  • Often asymptomatic at birth, but may cause skeletal abnormalities
  • Can present with craniotabes and osseous destruction of long bones, but not metaphyseal cupping and fraying
  • Other findings (eg, hepatosplenomegaly, rash, lymphadenopathy) are absent in this case

• (Choice E) Nonaccidental Trauma

  • Can present with localized swelling without reported trauma
  • New and/or old fractures would be expected on x-ray
  • Craniotabes would not be present in nonaccidental trauma cases

Learning Objective

Nutritional rickets classically occurs in exclusively breastfed infants who do not receive vitamin D supplementation. It presents with craniotabes (soft skull bones) and forearm deformities (widened wrists, radial/ulnar bowing). Lower extremity bowing develops once the child starts weight-bearing.