Independent lesions of fixed drug eruption caused by trimethoprim-sulfamethoxazole and tenoxicam in the same patient: a rare case of polysensitivity.

Abstract

Polysensitivity in fixed drug eruption is a rare finding that occurs because of chemically unrelated drugs. In cases of polysensitivity, the lesions may occur on identical or separate sites, the latter indicating the role of antigen-specific mechanisms in the site-specificity of fixed drug eruption. I herein report a patient with separate site involvement induced by trimethoprim-sulfamethoxazole and tenoxicam, a drug combination that has not been reported before. Reactivation of old trimethoprim-sulfamethoxazole-specific lesions after a long resting period was another striking feature.