A 16-year-old boy is presented to the emergency department (ED) with an 11-day history of low-grade fever. He complains of decreased appetite and a 7-lb weight loss during approximately the past 11 days. He denies any recent travel or unusual exposures. His symptoms began with an erythematous rash on his feet, bilateral ankle swelling, and pain while walking. The symptoms partially improved with the use of ice packs and bed rest. The patient was seen in his pediatrician's office with the same complaints 3 days ago; he was prescribed amoxicillin/clavulanate at that time, but he has not experienced any further improvement. The patient has no significant previous medical or surgical history, and he denies using alcohol, cigarettes, or other drugs. He lives in a residential urban home with his parents and sibling.
On the initial physical examination, he has a temperature of 100.9°F (38.3°C), but otherwise his vital signs are normal. His weight is noted to be in the third percentile for his age. Shoddy, deep cervical lymphadenopathy is present bilaterally, and asymmetrically enlarged, tender anterior cervical and submental lymph nodes are detected (more prominently on the left than right). He is noted to have a slightly scaly erythematous macular rash on his face and involving the bridge of the nose, with sparing of the nasolabial folds (see Figure 1; the image shown is not of the actual patient, but it exhibits the same findings as described in this case). The rash has sharp edges and is not pruritic. His physical examination is otherwise unremarkable.
The initial laboratory results reveal pancytopenia, with a white blood cell (WBC) count of 1.6 × 103/µL (1.6 × 109/L), a hemoglobin of 10.4 g/dL (104 gL), a hematocrit of 30%, and a platelet count of 71 × 103/µL (71 × 109/L). His erythrocyte sedimentation rate (ESR) is elevated at 80 mm/h. The patient is admitted to the hospital for fever of unknown origin. Cultures of blood, urine, and sputum are obtained, and he is subsequently started on broad-spectrum antibiotics. Serology tests for tick-borne illnesses, HIV, systemic lupus erythematosus (SLE), and Epstein-Barr virus (EBV) are sent. While awaiting the laboratory results, he is given 1 dose of intravenous immunoglobulin empirically for atypical Kawasaki disease, with no response. He is sent for bone marrow aspiration and biopsy, which shows hypocellular bone marrow for his age, with all 3 cell line elements present and without evidence of malignancy. Computed tomography (CT) imaging reveals bilateral axillary, anterior mediastinal, retroperitoneal, external iliac, supraclavicular, and inguinal lymphadenopathy (images not available). Biopsies of the left cervical and submandibular lymph node are performed, but they are not consistent with lymphoma or other malignancy.
Throat, urine, and blood cultures remain negative after 4 days. Antinuclear antibody (ANA) titers are positive, with a titer of 1:640 and a speckled appearance. The patient is scheduled for a second lymph node biopsy because of the incongruence of the radiographic and histologic studies. Prior to the procedure, bilateral small pleural effusions are discovered on the chest radiographs. As a result of his anemia and thrombocytopenia, he is transfused packed red blood cells and platelets, without marked improvement in these indices. A second bone marrow biopsy and left axillary lymph node biopsy are performed, but the results are unchanged from the prior biopsy results.
