Bathing suit ichthyosis (BSI) is a rare variant of autosomal recessive congenital ichthyosis (ARCI; see this term) characterized by the presence of large dark scales in specific areas of the body.
Less than 20 patients are reported in the literature.
This particular skin aspect appears after the sheading of a collodion membrane observed at birth. Contrarily to other forms of ARCI, the members (in exception of the folds) and the face are not affected by ichthyosis. Scales are present on warmer skin areas such as the trunk, the scalp, and the axillary region. On affected areas, the patient present with large dark scales similar to those observed in lamellar ichthyosis (LI).
BSI is caused by specific thermo-sensitive mutations in the TGM1 gene (encoding transglutaminase 1, involved in the cornification of the stratum corneum). Affected skin areas (warmer areas), show a clearly reduced enzyme activity in contrast to healthy skin areas that demonstrate an almost normal enzyme activity. Transmission is autosomal recessive.
Last update: January 2012
- Pr Juliette MAZEREEUW-HAUTIER