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 aureus or 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.