Makindo Medical Notes

Approximately 20% to 25% of untreated Kawasaki disease (KD) cases develop coronary artery abnormalities. There is evidence suggesting KD may result from an immune response to superantigen toxins, potentially from Staphylococcus aureusor Streptococcus pyogenes.

About

• Kawasaki disease is a rare, self-limiting vasculitis primarily affecting the coronary arteries.
• It is often underdiagnosed, especially in cases with atypical presentation.
• There may be a connection with Rickettsial disease, but the exact cause remains unclear.

Aetiology

• Untreated KD can lead to coronary artery aneurysms, which may cause occlusion and cardiac ischaemia.
• The disease can be fatal without intervention; approximately 80% of affected children are under 5 years old.

Clinical Presentation

• Most common age of onset is around 18 months.
• KD presents with a prolonged fever, typically lasting longer than 5 days, often reaching high temperatures (≥40°C).
• Other symptoms include unilateral cervical lymphadenopathy, peripheral edema, and skin desquamation.
• Characteristic signs include a “strawberry tongue” and a nonspecific truncal rash.

Investigations

• Lab tests often show elevated CRP, ESR, and platelet levels, reflecting systemic inflammation.

Diagnostic Criteria

• Required Criterion: Persistent fever lasting at least five days, often spiking, and resistant to typical antipyretics.
• Additional Criteria (4 out of 5 required):
• Extremity Changes: Redness, swelling, and induration of the hands and feet, followed by desquamation of fingers and toes one to three weeks after fever onset. Beau’s lines (white lines across nails) may appear 1-2 months post-illness.
• Polymorphic Rash: Various forms, including urticarial exanthem, morbilliform, target lesions, or diffuse scarlatiniform rash. Appears within five days of fever onset.
• Conjunctival Injection: Bilateral, painless, non-exudative redness of the conjunctivae.
• Oropharyngeal Changes: “Strawberry tongue,” cracked red lips, and erythema of the oropharynx. No mouth ulcers.
• Cervical Lymphadenopathy: Often unilateral, with firm, slightly tender nodes.
• Exclusion: Rule out other conditions with similar features.

Management

• IV Immunoglobulin (IVIG): Administered as early as possible; a dramatic response often aids in diagnosis.
• Aspirin: Given to reduce inflammation and prevent thrombosis.
• Note: Steroids are generally avoided due to an increased risk of coronary aneurysms.

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.