[Chronic lichenoid keratosis: disease variant or disease entity?]

The presentation of a new case of keratosis lichenoides chronica (KLC) in a 61-year-old woman lead us to this comprehensive study of the cases already published in the literature. The clinical and histological substrate of KLC and its differential diagnosis and treatment are discussed in detail. The clinical appearance is mainly characterized by an eruption of (1) lichenoid, keratotic papules, (2) linear or plaque-like keratosis, and (3) psoriasis-like scaling lesions on the trunk and extremities. The course of the disease is chronic and progressive. Histopathological study shows variable features, which are similar to those of lichen planus only on rare occasions. This dermatosis does not show any pathological relationship with other dermatological conditions; we therefore suggest that KLC is a distinct entity.