THE CASE
A previously healthy 3-year-old girl presented to the emergency department with 4 days of fever and 2 days of right-side neck pain. The maximum temperature at home was 103 °F. The patient was irritable and vomited once. There were no other apparent or reported symptoms.
The neck exam was notable for nonfluctuant, swollen, and tender lymph nodes on the right side. Her sclera and conjunctiva were clear, and her oropharynx was unremarkable. Lab work revealed leukocytosis, with a white blood cell (WBC) count of 15.5 × 103/µL (normal range, 4.0-10.0 × 103/µL). She was given one 20 cc/kg normal saline bolus, started on intravenous clindamycin for presumed cervical lymphadenitis, and admitted to the hospital.
On Day 2, the patient developed a fine maculopapular rash on her chest, abdomen, and back. She had spiking fevers—as high as 102.2 °F—despite being on antibiotics for more than 24 hours. The erythrocyte sedimentation rate (ESR) was 39 mm/h (0-20 mm/h), and C-reactive protein (CRP) was 71.4 mg/L (0.0-4.9 mg/L). Due to concern for abscess, a neck ultrasound was performed; it showed a chain of enlarged lymph nodes in the right neck (largest, 2.3 × 1.1 × 1.4 cm) and no abscess.
On Day 3, clindamycin was switched to intravenous ampicillin/sulbactam because a nasal swab for methicillin-resistant Staphylococcus aureus was negative. A swab for respiratory viral infections was also negative. The patient then developed notable facial swelling, bilateral bulbar conjunctival injection with limbic sparing, and swelling of her hands and feet.
THE DIAGNOSIS
By the end of Day 3, the patient’s lab studies demonstrated microcytic anemia and low albumin (2.5 g/dL), but no transaminitis, thrombocytosis, or sterile pyuria. An electrocardiogram was unremarkable. A pediatric echocardiogram revealed hyperemic coronaries, indicating inflammation. The coronary arteries were measured in the upper limits of normal, and the patient’s Z-scores were < 2.5. (A Z-score < 2 indicates no involvement, 2 to < 2.5 indicates dilation, and ≥ 2.5 indicates aneurysm abnormality.1) An ultrasound of the right upper quadrant revealed an enlarged/elongated gallbladder. The patient therefore met clinical criteria for Kawasaki disease.
DISCUSSION
Kawasaki disease is a self-limited vasculitis of childhood and the leading cause of acquired heart disease in children in developed countries.1 The annual incidence of Kawasaki disease in North America is about 25 cases per 100,000 children < 5 years of age.1 In the United States, incidence is highest in Asian and Pacific Islander populations (30 per 100,000) and is particularly high among those of Japanese ancestry (~200 per 100,000).2 Disease prevalence is also noteworthy in Non-Hispanic African American (17 per 100,000) and Hispanic (16 per 100,000) populations.2
Diagnosis of Kawasaki disease requires presence of fever lasting at least 5 days and at least 4 of the following: bilateral bulbar conjunctival injection, oral mucous membrane changes (erythematous or cracked lips, erythematous pharynx, strawberry tongue), peripheral extremity changes (erythema of palms or soles, edema of hands or feet, and/or periungual desquamation), diffuse maculopapular rash, and cervical lymphadenopathy (≥ 1.5 cm, often unilateral). If ≥ 4 criteria are met, Kawasaki disease can be diagnosed on the fourth day of illness.1
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