Heparin-induced thrombocytopenia during IgA vasculitis: a case report.

Immunoglobulin A (IgA) vasculitis is characterized by small vessel vasculitis involving immune complexes and IgA deposition. The development of heparin-induced thrombocytopenia (HIT) during IgA vasculitis is extremely rare. An 87-year-old man presented with general fatigue, leg edema, purpura, arthritis and renal disease. He was diagnosed with IgA vasculitis and was admitted to our hospital. Hemodialysis with heparin was initiated thrice a week on post-admission Day 11. On Day 21, during hemodialysis, the pressure in the dialysis circuit increased and the dialysis was interrupted. On Day 24, the platelet count rapidly decreased to 18 000/μl. The patient was diagnosed with HIT after testing positive for HIT antibodies; heparin was discontinued at this time. Precautions must be taken against the onset of HIT when initiating hemodialysis in patients with IgA vasculitis.