Disseminated superficial porokeratosis.

A 65-year-old male diabetic presented with erythematous and hyperpigmented plaques with scaling and crusting involving the trunk and extensor surfaces of extremities of 10 years duration associated with mild itching. Cutaneous examination revealed large hyperpigmented and erythematous plaques with raised borders over the trunk and extremities. A small plaque on the (L) forearm showed a raised thread like margin with a furrow. A provisional diagnosis of disseminated superficial porokeratosis was made. Skin biopsy confirmed the diagnosis of disseminated superficial porokeratosis.