Bathing suit ichthyosis.

Bathing suit ichthyosis (BSI) is a rare variant of autosomal recessive lamellar ichthyosis due to transglutaminase-1 (TGase-1) gene mutations leading to a temperature sensitive phenotype. It is characterized by dark-grey or brownish scaling restricted to the 'bathing suit' areas, whereas the extremities and central face are almost completely spared. We report a 2-year-old African girl with BSI with ultrastructural and biochemical demonstration of TGase-1 deficiency over the affected skin. TGase-1 gene analysis disclosed the homozygous p.R315L mutation, which may lead to a temperature sensitive dysfunction of the enzyme.