Epidermolytic hyperkeratosis with palmoplantar keratoderma in a patient with KRT10 mutation.

We report the case of a 12-year-old girl presenting at birth with erythroderma, erosions and blisters scattered over the integument. By the age of 3 she presented generalized hyperkeratotic plaques with a cobblestone pattern and a pungent odour, most prominently around flexures, scalp and palmoplantar areas. Clinical, histological and ultrastructural findings confirmed the diagnosis of epidermolytic hyperkeratosis (EHK). Molecular genetic analysis revealed a mutation in the KRT10 gene. Treatment with oral acitretin was attempted but it was discontinued due to hepatic dysfunction and marked desquamation and blistering. EHK is a rare autosomal dominant disorder of keratinization, caused by mutations in either the KRT1 or KRT10 genes. Although palmoplantar keratoderma is typically found in patients with KRT1 mutation, our patient presents EHK with palmoplantar involvement and KRT10 mutation. Moreover, a poor response to systemic retinoids was observed, contrary to what is expected in patients with KRT10 mutation. Even though management is usually unsatisfactory, some patients with this lifelong and serious condition may experience improvement with age.