Plasmodium Vivax Malaria: Usual Illness with Dysregulated Immune Profile

Afebrile Plasmodium vivax disease is believed to be extremely rare; and so is the association of a secondary immune thrombocytopenia due to Plasmodiun vivax malaria. This is a case of malaria presenting in an atypical manner. A middle aged male (31 years) came with occasional bleeding around gums, small petechial haemorrhages over chest and abdomen, and blood in stools for a few months, but no fever. In addition, the cervical lymph nodes were slightly enlarged. Spleen was 3 cm below costal margin. Platelets were found to have markedly decreased with clusters of megakaryocytes in the bone marrow. A possibility of Immune thrombocytopenic purpura was considered and immunoglobulin started intravenously, however platelet counts remained low. Later, in a follow up smear, trophozoites of P. vivax were discovered. Antimalarial drugs (Artesunate) were administrated for the patient along with IV immunoglobulins, to which he responded. It was revealed by flow cytometry that the ratio of helper to cytotoxic cells was reversed (0.9). This highlighted a rare case of afebrile malaria in association with immune dysregulation. Accordingly, malaria, though uncommon, could trigger immune thrombocytopenia.