Keratosis lichenoides chronica in pediatric patients: a different disease?

Keratosis lichenoides chronica (KLC) is a rare acquired disease of adulthood, of unknown etiology, characterized by keratotic parallel linear lesions, retiform plaques, and keratotic, often follicular papules, chronicity and lichenoid histopathologic features. KLC of pediatric onset is considered extremely rare. Its features and relationship to adult onset KLC are unknown. We studied 8 cases of pediatric-onset KLC in the literature and 6 personal cases and compared them with 40 reported adult-onset KLC patients. The following features characterize pediatric-onset KLC: familial occurrence; probable autosomal recessive inheritance; early or congenital onset with facial erythemato-purpuric macules; forehead, eyebrow, and eyelash alopecia; pruritus; and a low frequency of other cutaneous and systemic abnormalities. Pediatric-onset KLC may represent a different disease or a subset of adult-onset KLC, with special genetic and clinical characteristics. Determining its precise nosology will have prognostic and therapeutic implications.