Thrombocytopenia associated with histoplasmosis and an elevated platelet associated IgG.

A patient with primary pulmonary histoplasmosis, symptomatic thrombocytopenia, and an associated elevation of platelet associated IgG during the acute phase of the illness is described. Whereas thrombocytopenia has been reported previously in patients with disseminated histoplasmosis, it appears that thrombocytopenia in a patient with nondisseminated histoplasmosis has not been described. Although certain clinical findings suggested idiopathic thrombocytopenic purpura, corticosteroids were not administered, and lymph node biopsy documented the presence of Histoplasma capsulatum. Similarly, elevated platelet associated IgG levels apparently have not been reported previously in thrombocytopenic patients with histoplasmosis. Possible mechanisms for thrombocytopenia associated with histoplasmosis are discussed.