Severe thrombocytopenia and response to corticosteroids in a case of nephropathia epidemica

Nine days after working in the woods, a previously healthy 32-year-old man fell seriously ill. His symptoms included high fever, chills, diffuse myalgia, severe headache, and back pain. On the fifth day of onset of symptoms, blood tests showed creatinine levels of 5.4 mg/dL accompanied by marked proteinuria. After admission to the hospital, a diagnosis of nephropathia epidemica (NE) caused by Puumala virus was made using solid-phase enzyme-linked immunosorbent assay (ELISA). The patient gradually recovered renal function without requiring dialysis. However, he surprisingly experienced a sharp decline in platelet count to a minimum of 2,000/microL with concomitant occurrence of petechiae and conjunctival hemorrhage. Prednisolone was initiated, resulting in a swift rise in platelets. Six days later, when the medication was withdrawn, a sharp decrease in platelets recurred. The steroids were then readministered for the next 3 months, thus reestablishing a stable platelet count. The immediate rise of platelets after administration of prednisolone supports the pathophysiological view of hantavirus infection as an immunologically mediated disease. Corticosteroids in the treatment of hantavirus-associated thrombocytopenia might need further systematic evaluation.