Keratosis linearis with ichthyosis congenita and sclerosing keratoderma (KLICK) is an autosomal recessive disorder of keratinization characterized by ichthyosis, palmoplantar keratoderma with constricting bands around fingers, flexural deformities of fingers, and keratotic papules in a linear distribution on the flexural side of large joints. Histologic examination shows hypertrophy and hyperplasia of the spinous, granular, and horny epidermal layers, with abundant abnormal keratohyaline granules in differentiated keratinocytes (summary by Dahlqvist et al., 2010).