Thrombocytopenia in a bisexual adolescent male with a history of intravenous drug use.

Immunologically mediated thrombocytopenia has been reported as a manifestation of human T-lymphotropic virus type III (HTLV-III) infection and intravenous (IV) drug abuse. The case report describes thrombocytopenia in a bisexual adolescent male with antibody to the HTLV-III virus and a history of infrequent IV drug abuse. The case underscores the need to consider HTLV-III infection and/or IV drug abuse in the differential diagnosis of thrombocytopenia in an adolescent.