Bathing suit ichthyosis Q80.2

Bathing suit ichthyosis (BSI) is a special form of autosomal recessive congenital ichthyosis. Due to temperature-sensitive mutations in the transglutaminase-1 gene, previously generalized autosomal recessive ichthyosis lamellosa with transglutaminase deficiency results in healing of skin lesions at sites of intense cooling (arms, legs, face), whereas areas normally covered by a bathing suit are affected.

Thus, the severity of ichthyosis also depends on the seasons (increased in summer).

BSI is caused by a deficiency of transglutaminase-1 (TGase-1). More than 13 mutations in the TGM1 gene have now been identified (predominantly missense mutations). In situ TGase tests in the skin of BSI patients showed a marked decrease in enzyme activity when the temperature was raised from 25 to 37 degrees Celsius.

1. Benmously-Mlika R et al (2014) Bathing suit ichthyosis caused by a TGM1 mutation in a Tunisian child. Int J Dermatol 53:1478-1480.
2. Oji V et al (2006) Bathing suit ichthyosis is caused by transglutaminase-1 deficiency: evidence for a temperature-sensitive phenotype. Hum Mol Genet 15:3083-3097.