Brucellosis Presenting as Immune-mediated Thrombocytopenia in a Young Indian Male

Brucellosis has previously been described to cause thrombocytopenia through various mechanisms, but an autoimmune phenomenon secondary to molecular mimicry has been infrequently reported in a handful of case reports. We present a case of a young male with no significant past medical history who presented with bleeding from his gums, the presence of black, tarry stools, petechial skin rashes, and epistaxis persisting over four weeks. Physical examination revealed pallor and splenomegaly. Preliminary investigations showed low red blood cells and platelet counts. A working diagnosis of immune thrombocytopenia (ITP) was made, and management was initiated with methylprednisolone and intravenous immunoglobulins; however, the platelet counts remained low despite the intervention. Further workup revealed increased megakaryocytes on bone marrow biopsy. Serum Brucella IgM was positive. Given this, doxycycline and gentamicin were initiated, resulting in marked improvement in cell counts after a week of therapy. Hence, a high clinical suspicion for brucellosis should be maintained in cases of isolated thrombocytopenia, especially in endemic areas.