Epidermal keratinization disorders comprise a heterogeneous group of skin diseases that share the common feature of abnormal epidermal maturation, often leading to a disturbed stratum corneum.

To describe two cases of an unusual disorder of epidermal keratinization.

The clinical features of two unrelated patients with a long-standing widespread cutaneous eruption are described. Histopathologic examination and immunohistochemical studies were performed on skin biopsy specimens.

The eruption was characterized by symmetric erythematous, flat, discrete papules with a polygonal shape and fine scaling. The papules covered most of the skin surface and, in some areas of the trunk, they were arranged along the lines of cleavage, parallel to the ribs. There was no facial, mucosal, nail, or palmoplantar involvement; the teeth and hair were normal. The first patient had a sister with an identical eruption, and a brother of the second patient was said to have similar skin lesions. Histopathology revealed well-demarcated areas of compact eosinophilic orthokeratotic hyperkeratosis overlying a slightly acanthotic epidermis. Lesional skin showed weaker immunoexpression for connexin 43 compared with normal skin.

Only two patients and one sibling were investigated.

We propose the name “saurian papulosis” to describe this newly described clinicopathologic entity.