A 61-year-old who was receiving long-term treatment with prednisone for refractory idiopathic thrombocytopenic purpura required a dose increase after a large decrease in platelet count (6×109/L).
He had had his spleen removed 7 years earlier. He was not on any other medication and there was no evidence of pseudothrombocytopenia, lymphoprolipherative disease, malignancies, or Mycobacterium tuberculosis infection.
Serological tests were negative for HIV, Epstein Barr virus, cytomegalovirus, antinuclear antibodies, and lupus anticoagulant. Stool specimen was negative for Helicobacter pylori.
24 h later he developed pigmented vesicles on the left side of his trunk, left arm, and left hand.
What’s the Diagnosis ?