A case report is presented of a 59-year-old white woman with a ten-year history of recurrent episodes of crural fungus infections with secondary erythematous-edematous lesions of the buttocks, thighs, forearms, and flexor surfaces of the elbows and knees. Trichophyton gypseum was cultured from the crural lesions, and intracutaneous testing with trichophytin extracts resulted in an immediate positive wheal-flare response and a negative forty-eight-hour delayed type reaction. The presence of circulating reagins to trichophytin could not definitely be proved. Evidence is presented to suggest that this represents an unusual type of dermatophytid characterized by fixed tissue sensitization. The secondary erythematous-edematous “id” lesions responded dramatically to orally administered hydrocortisone, while the primary fungus infection was unaffected by the adrenal corticosteroid therapy.