A 15-month-old With Fever and Malaise
Forty-eight hours after starting antibiotics, the patient remained febrile and she again presented to the pediatric clinic. Vital signs demonstrated a temperature of 38.7°C, heart rate of 183 beats/min, blood pressure of 100/45 mm Hg, respiratory rate of 50 breaths/min and oxygen saturation of 98%. Physical examination was notable for fissured lips, desquamation of the palmar surfaces without edema, tachycardia without murmurs, tachypnea with clear lung fields and a mildly erythematous right tympanic membrane without bulging or signs of effusion. There was no bulbar conjunctival injection, polymorphous rash or cervical lymphadenopathy.
She was admitted from clinic to the general pediatric hospital service. Upon admission, laboratory evaluation demonstrated anemia (hemoglobin of 9.7 mg/dL), leukocytosis (white blood cell count of 27.3 × 109/L) with neutrophil predominance (77% neutrophils, 20% lymphocytes, 2% monocytes and 1% myelocytes), normal platelet count (411 × 109/L), elevated C-reactive protein of 135 mg/L (normal <3.0 mg/L), erythrocyte sedimentation rate of 58 mm/h (normal <29 mm/h) and normal alanine aminotransferase level (15 U/L). Urinalysis demonstrated 1–3 white blood cells per high-power field without casts or red cells. Nasopharyngeal swabs for respiratory syncytial virus, influenza and adenovirus were negative by polymerase chain reaction (PCR). A throat swab was positive for group A Streptococcus by PCR. An echocardiogram showed no evidence of coronary artery ectasia or aneurysmal dilation. Biventricular systolic function was normal with no mitral regurgitation or pericardial effusion. Given the clinical concern for incomplete Kawasaki disease, empiric treatment with intravenous immunoglobulin at 2 g/kg and high-dose aspirin was initiated. Fever persisted after 48 hours with a new-onset blanchable, erythematous, maculopapular rash over the face and shotty, nontender, mobile, right-sided cervical adenopathy without overlying erythema or swelling. The largest cervical lymph node was estimated to be 1 cm in diameter. Treatment with intravenous immunoglobulin was repeated at 2 g/kg.
She remained febrile for 5 days and completed the 10-day course of amoxicillin-clavulanate on day 16 of illness. On day 18 of illness, fever recurred and chest radiography showed severe enlargement of her cardiothymic silhouette. Echocardiogram demonstrated a large, hemodynamically significant circumferential pericardial effusion. An emergency pericardiocentesis was performed with drainage of a hemorrhagic effusion. Aerobic, anaerobic, fungal and mycobacterial cultures of the pericardial fluid were negative. Testing for parvovirus, herpes simplex virus, cytomegalovirus, Epstein-Barr virus, human herpes virus-6 and Mycoplasma pneumoniae were all negative by PCR. Computed tomography (CT) of the chest was performed, revealing the diagnosis.