[Two faces of Janus. Coexistence of systemic lupus erythematosus and psoriasis in the same patient].

While both lupus erythematosus and psoriasis are inflammatory dermatoses characterized by scaly erythematous plaques, they are rarely confused in clinical practice. We report a woman who alternately presented with lupus erythematosus and psoriasis over 14 years but the former condition was not recognized and adequately treated. After the complete diagnosis had been established, a combination of thalidomide and acitretin resulted in a prolonged remission of both disorders. This unusual case demonstrates that coexistence of two diseases in one patient presents a diagnostic challenge that can only be met by repeated careful correlation of all clinical and histopathologic findings. It is of particular importance if these diseases require conflicting management strategies.