Persistent fever in an infant: incomplete Kawasaki disease.

CMAJ, November 22, 2011, 183(17) 2009 Afour-month-old white girl presented to her local hospital when her parents noticed that her left upper extremity had turned blue from her midforearm to her fingertips. When she was nine weeks old, a persistent fever had developed associated with a patchy macular rash extending over her trunk and extremities. The fever had responded transiently to antipyretics but recurred and persisted for two weeks, when both the fever and rash resolved. Still, she did not recover clinically, and her parents found her fussy and inconsolable. In addition, her parents were concerned about her red, cracked lips. She was transported from the local hospital to our pediatric intensive care unit, where our observation unit is located. On admission, the patient was afebrile and extremely fussy with stable hemodynamics (heart rate was 160 beats/min, levels of oxygen saturation ranged from 92% to 94% on room air and systemic blood pressure was 86/42 mm Hg). She had diminished brachial and radial pulses in her left arm with easily palpable right brachial, radial and femoral pulses. On her left hand, her distal fingers were black (Figure 1). Her lips were erythematous and cracked, but there were no features of conjunctivitis, lymphadenopathy or rash. Auscultation of the lungs was clear. Her precordium was active with normal heart sounds, a soft gallop and a grade III of VI regurgitant murmur at the apex radiating to the axilla. Her liver edge was palpable 2 cm below the costal margin. Results of laboratory investigations showed marked elevation of her inflammatory markers (C-reactive protein level was 176 [normal < 5] mg/L, erythrocyte sedimentation rate was 46 [normal 0–30] mm/h). She was anemic (hemoglobin level was 82 [normal 95–135] g/L) with an elevated leukocyte count of 36.9 (normal 5.0– 17.5) × 10/L and hypoalbuminemia (albumin level was 28 [normal 34–42] g/L). She had sterile pyuria. Serum transaminase levels and platelet count were normal. A workup for infection was negative. A chest radiograph showed cardiomegaly with increased pulmonary vascular markings. A 12-lead electrocardiogram showed biventricular hypertrophy with no features suggestive of ischemia. An echocardiogram showed mitral regurgitation, a small pericardial effusion and giant aneurysms of the coronary artery. Left ventricular function was preserved, with normal ejection and shortening fractions and no obvious segmental dyskinesis. Based on our patient’s history of prolonged fever, rash, erythematous lips, signs of systemic inflammation and coronary aneurysms, we diagnosed incomplete Kawasaki disease. We started treatment with intravenous immunoglobulin, along with a three-day course of pulse methylprednisolone as rescue therapy, recognizing that she was already in the subacute phase of her illness. Cases