Chronic pigmented purpura associated with odontogenic infection.

Five patients with chronic pigmented purpura associated with odontogenic infection are described. Four patients had Schamberg's disease, and one had itching purpura. These patients were resistant to topical corticosteroid treatment, but appearance of purpuric spots ceased after treatment for periodontitis, pulpitis, or both. No circulating immune complexes were detected, and neither immunoglobulin nor complement was deposited in the papillary vessels of the skin. Odontogenic infection might be one of the precipitating factors for chronic pigmented purpura.