By Gary M. White, MD
Lamellar ichthyosis (LI) is an autosomal recessive congenital ichthyosis (ARCI) which in many patients is caused by mutations in the gene encoding the transglutaminase 1 (TGM1) enzyme, which is responsible for assembly of the cornified envelope. Usually, inheritance is AR.
The patient may present as a collodion baby at birth. Over time, the skin develops large, plate-like ichthyotic scales. Many patients develop a keratoderma and/or ectropion. There may be cicatricial alopecia. Heat intolerance, hypohidrosis, delayed development, and an increased risk of infection have been reported. There is a subset with a “bathing trunk” distribution due to a temperature-sensitive mutation in TGM1 [Hum Mol Genet 2006;15:3083].
Retinoids are dramatically helpful (e.g., acitretin) but side effects limit their long term use. Excellent results were obtained in 4/6 patients in one study of oral isotretinoin. The dose was 0.6 mg/kg body weight initially with the dose gradually increased up to 1 mg/kg body weight depending on severity and response to treatment [Indian J Paediatr Dermatol 2016;17:125-8]. Topical tazarotene was very helpful within weeks in one case report. Topical calcipotriol had a beneficial effect in one study. Galderma has received orphan status for trifarotene, a selective agonist of the retinoic acid receptor gamma (RAR-gamma) and is investigating it in the treatment of lamellar ichthyosis.
Tazarotene cream once or twice daily appears to be effective in the management of ectropion and lagophthalmos in the setting of LI in children, even in the neonatal period [PD 2017;34;584].
Ectropion in LI. Indian J Dermatol Venereol Leprol 2015;81:32