Makindo Medical Notes

⚠️ Around 20–25% of untreated Kawasaki disease (KD) cases develop coronary artery abnormalities. KD may represent an immune response to bacterial superantigens (Staphylococcus aureus, Streptococcus pyogenes).

🧾 About

• Rare, self-limiting vasculitis that primarily targets the coronary arteries.
• Often underdiagnosed, especially when presentation is atypical.
• Exact cause is uncertain, though infectious and immune mechanisms are suspected.
• ~80% of cases occur in children under 5 years, with a peak around 18 months.

🧬 Aetiology

• Immune-mediated vascular injury → risk of coronary artery aneurysms.
• Untreated disease can lead to occlusion, ischaemia, myocardial infarction, or even death.

🔎 Clinical Presentation

• Prolonged high fever (>5 days, often ≥40°C).
• Unilateral cervical lymphadenopathy (firm, slightly tender).
• Peripheral oedema, followed by desquamation of hands/feet.
• “Strawberry tongue”, cracked lips, erythematous oropharynx.
• Polymorphic rash on trunk (scarlatiniform, morbilliform, target lesions).
• Bilateral painless conjunctival injection (non-exudative).

📋 Diagnostic Criteria

Essential: Persistent fever ≥5 days (spiking, unresponsive to antipyretics).
Plus 4 out of 5:

1. 👣 Extremity changes (erythema, oedema → peeling/desquamation, Beau’s lines later).
2. 🌸 Polymorphic rash (early, variable morphology).
3. 👀 Conjunctival injection (bilateral, painless, non-purulent).
4. 👅 Oral changes (strawberry tongue, cracked lips, erythematous mucosa, no ulcers).
5. 🧑‍🦱 Cervical lymphadenopathy (usually unilateral).

Always exclude: scarlet fever, measles, viral exanthems, Stevens–Johnson syndrome, toxic shock.

🧪 Investigations

• Bloods: ↑ CRP, ↑ ESR, ↑ platelets (after day 7), mild anaemia, neutrophilia.
• Echo: Assess coronary artery involvement (baseline + follow-up).
• Rule out other infections: throat swab, serology, viral PCR as indicated.

💊 Management

• IVIG: 2 g/kg as early as possible → reduces coronary aneurysm risk.
• Aspirin: High-dose initially (anti-inflammatory), then low-dose (antiplatelet).
• Steroids: Generally avoided, as they may ↑ aneurysm risk.
• Ongoing cardiology follow-up for coronary monitoring.

📚 References

• Dajani AS, Taubert KA, Gerber MA, Shulman ST, Ferrieri P, Freed M, et al. Diagnosis and therapy of Kawasaki disease in children. Circulation. 1993;87:1776-80.

Cases — Kawasaki Disease

• Case 1 — Classic presentation 👶: A 3-year-old boy presents with 6 days of high fever unresponsive to paracetamol. Exam: bilateral conjunctival injection, red cracked lips, strawberry tongue, and polymorphous rash. Cervical lymph node 2 cm palpable. Diagnosis: Kawasaki disease (meets ≥5 criteria). Managed with IV immunoglobulin and high-dose aspirin.
• Case 2 — Incomplete Kawasaki ⚠️: A 9-month-old girl presents with persistent fever for 7 days, irritability, and oedematous hands/feet. She has conjunctivitis and rash but does not meet full diagnostic criteria. Echocardiogram: coronary artery dilatation. Diagnosis: incomplete Kawasaki disease. Managed with IVIG, aspirin, and close cardiology follow-up.
• Case 3 — Coronary aneurysm complication ❤️: A 5-year-old boy treated for Kawasaki disease at day 12 of illness (delayed presentation) develops exertional chest pain 6 weeks later. Echocardiogram: giant coronary artery aneurysms. Diagnosis: Kawasaki disease complicated by coronary artery aneurysms. Managed with dual antiplatelet therapy ± anticoagulation, and long-term cardiology care.

Teaching Point 🩺: Kawasaki disease is an acute systemic vasculitis of childhood. Diagnostic features: fever ≥5 days + ≥4 of: conjunctivitis, oral changes, rash, cervical lymphadenopathy, extremity changes. ⚠️ Main risk: coronary artery aneurysms. Treatment = IVIG within 10 days + high-dose aspirin (then low-dose until platelet normalisation/cardiology clearance).