A newborn is delivered encased in a tight, shiny 'collodion membrane' that cracks and peels within weeks. The most likely underlying diagnosis is:

• A Lamellar ichthyosis or non-bullous congenital ichthyosiform erythroderma — TGM1 or ALOX12B mutations ✓
• B Epidermolytic hyperkeratosis (bullous ichthyosiform erythroderma) — KRT1/KRT10 mutations
• C Harlequin ichthyosis — ABCA12 mutation
• D X-linked ichthyosis — STS (steroid sulfatase) deficiency

Explanation

A collodion baby is a non-specific phenotype most commonly evolving into lamellar ichthyosis (LI) or non-bullous congenital ichthyosiform erythroderma (NBCIE). LI is most often caused by TGM1 mutations (transglutaminase-1 deficiency), ALOX12B, or NIPAL4, inherited as autosomal recessive. The collodion membrane causes restricted respiration, feeding difficulty, temperature dysregulation, and infection risk in the neonatal period. Harlequin ichthyosis (ABCA12) presents more severely with thick armour-plate scales and not as a thin collodion film.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.