Congenital ichthyosis is a clinically and genetically heterogeneous group of disorders of keratinization characterized by a significant and incapacitating scaling of the skin. Most forms are congenital and display different modes of inheritance. Among them, autosomal recessive lamellar ichthyosis is a severe condition with an estimated prevalence of 1 per 200,000 newborns, presenting a 'collodion-baby' syndrome at birth: the newborn is embedded in a hyperkeratotic skin. Spontaneous shedding of the membrane leaves residual ichthyosis and may lead to grave sequela, such as joint contractures, ectropion and secondary corneal involvement. Sometimes during adulthood, scarring alopecia, palmoplantar keratoderma and associated erythroderma are observed, and are therefore features of phenotypic variability.