A 58-year-old man complained of an asymptomatic scaly, erythematous rash that had been present for five years. The presumptive diagnosis was eczema or psoriasis. Prior biopsies had been nondiagnostic and topical corticosteroids had been only sporadically beneficial. Early lesions had involved only his buttocks; now more than 70% of his total skin surface was involved. Extensive erythematous, hypopigmented and hyperpigmented scaly patches as well as thin plaques were seen on his trunk and limbs.