A Case of Anaphylactoid Purpura with a Clinical Appearance of Annular Purpura

A 51-year-old woman visited our hospital in 1996 because of painful annular purpuric patches on her lower limbs. The eruptions spread centrifugally and did not respond to antibiotics. A skin biopsy of the marginal ridge of the annular purpura revealed leukocytoclastic vasculitis in the upper dermis and a blood examination revealed a slightly elevated serum IgA level. She was diagnosed to have anaphylactoid purpura. The eruptions showed a good response to corticosteroid therapy and eventually resolved within a few weeks. No recurrence has been observed after the therapy.