Progressive symmetric erythrokeratoderma (PSEK), also known as Darier-Gottron syndrome, is a rare genodermatosis that is usually autosomal dominantly inherited, although autosomal recessive inheritance has been reported. Since it was initially described in 1911, fewer than 100 cases have been reported in the literature.

PSEK kindreds have been shown to have underlying varied gene mutations, including in the loricrin gene, the GJB4 gene (the gene affected in erythrokeratodermia variabilis), and the 3-ketodihydrosphingosine reductase (KDSR) gene, among others.

PSEK is characterized by well-demarcated, erythematous, hyperkeratotic plaques that are symmetrically distributed on the extremities and buttocks and that can progress to involve the face, trunk, and abdomen. PSEK usually develops shortly after birth or during infancy. It progresses throughout childhood and stabilizes after puberty. It has the propensity to improve after puberty but sometimes persists into adulthood.

In around half of cases, there is an associated palmoplantar keratoderma. A single kindred manifested pseudoainhum in association. A kindred with KDSR mutations manifested thrombocytopenia in association.