Well-circumscribed eroded lesions on the palms of a middle-aged woman

A 58-year-old woman presented with a 2-year history of well-circumscribed erythematous lesions associated with a burning sensation on the palmar aspect of both hands. There was no history of trauma to the affected areas. Histopathological examination of the plaque on the left thenar eminence revealed a sharp step in the corneal layer with hypokeratosis in the left half of the field. There was no response to treatment with potent topical steroids, topical calcineurin inhibitors or antifungals. Owing to its rarity, this condition presents both a diagnostic and therapeutic challenge to dermatologists.