Fever, Hemolytic Anemia, and Bleeding Skin Lesions After Travel to the Andes

A 24-year-old previously healthy man presents with 9 days of high fevers, profound fatigue, headache, diffuse myalgias, and progressive dyspnea on exertion. He reports dark urine for 3 days and near-syncope when climbing stairs. He returned 3 weeks ago from a rural valley in the Peruvian Andes, where he stayed in adobe housing without window screens and reported frequent nighttime insect bites. He did not take malaria prophylaxis and has no known chronic immunocompromising condition.

Physical exam shows an ill-appearing, markedly pale patient with mild scleral icterus. Vital signs are temperature 39.4 C, blood pressure 96/58 mmHg, heart rate 126/min, respiratory rate 24/min, and oxygen saturation 95% on room air. He has conjunctival pallor, a flow systolic murmur, and mild right upper quadrant tenderness. There is no nuchal rigidity, no focal neurologic deficit, and no rash at initial presentation.

Initial laboratories show severe anemia (hemoglobin 6.1 g/dL), thrombocytopenia, indirect hyperbilirubinemia, elevated LDH, and low haptoglobin, consistent with active hemolysis. A peripheral blood smear demonstrates pleomorphic bacillary forms associated with erythrocytes, and early blood cultures are unrevealing.

He is treated and initially improves clinically, but several weeks later develops crops of friable red-violaceous papules and nodules on the extremities that bleed with minor trauma, consistent with the eruptive phase of disease.