Kawasaki Disease in Two Siblings of a Sub-Saharan Family

Kawasaki disease (KD) is an acute systemic vasculitis that predominantly affects children under 5 years old. Its major complication is the development of coronary arteries aneurysms. The underlying aetiology is still unknown but supposed to be a complex interplay of genetic susceptibility and/or an activation of the immune system triggered by an infection. We report hereby the case of one Cameroonian family with 2 KD-affected siblings.

A girl of 8 months developed high fever since 9 days associated with cough, bilateral non-purulent conjunctivitis, cheilitis and impaired of general status. Laboratory features showed anemia, thrombocytosis, neutrophilia, high sedimentation rate and hyponatremia. Echocardiography revealed diffuse aneurysm formations of the coronary arteries. KD was suspected and the evolution is favourable under intravenous immunoglobulin (IVIG) and high-dose aspirin.

Her younger brother was diagnosed with KD 18 months later at 11 months old. He presented high fever since 3 days, with cervical lymphadenopathy and all mucocutaneous tissues alterations of the KD. IVIG and high-dose aspirin were given at the 7^th day from the initial fever with prompt defervescence. Unfortunately, coronary aneurysm was observed 20 days after the initial symptoms.

KD occurs worldwide with the highest incident in Japan and Korea. The incidence rates of KD were about 265 and 217 cases per 100,000 children under 5 years of age respectively. In contrast, in the United States, the estimated figure was lower at 19-25 per 100,000. In Japan, siblings’ cases are well recognised. The risk is increased by 2 when the parents are affected with KD and by 10 in siblings of an index case. Furthermore, studies from Japan also suggest a higher risk of developing coronary artery lesions with families with multiple affected members.

Further genetic researches are needed to understand the physiopathology of KD. They could therefore lead to an improvement of its management.