Successful treatment of generalized inflammatory linear verrucous epidermal nevus with a somatic mutation in KRT10 with crisaborole 2% ointment.

Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare skin disorder characterized by pruritic, erythematous, hyperkeratotic papules and plaques following the lines of Blaschko. Pathogenesis of ILVEN is not yet clear and treatment remains challenging. We analyzed the molecular basis of generalized ILVEN in a Chinese girl and evaluated the therapeutic effect of topical crisaborole 2% ointment. The patient was found to carry a somatic heterozygous c.467G > A (p.Arg156His) mutation in the KRT10 gene. Expressions of IFN-γ, IL-12, IL-23 and IL-17A at mRNA level in her lesions were elevated. An excellent response was achieved after application of crisaborole 2% ointment. Our data reveal the crucial role of activation of immune response in the development of ILVEN with somatic KRT10 mutations, and suggest crisaborole 2% ointment should be considered for the treatment of ILVEN.