Trichothiodystrophy (TTD) is a rare autosomal recessive disorder characterized by sulfur-deficient brittle hair, which may be isolated or associated with a wide spectrum of neuroectodermal abnormalities.1 Although not pathognomonic,2 the finding of alternately dark and light oblique bands in a "tiger tail" pattern of the hair shaft on polarized light microscopic examination is a highly suggestive sign of the disorder and usually provides the clue for the diagnosis.
Trichothiodystrophy may be associated with the cellular defect in DNA repair of the xeroderma pigmentosum complementation group D (XPD). Trichothiodystrophy-XPD syndrome (TTD-XPD) is characterized by premature birth, ichthyosis with nail dystrophy, physical and mental retardation, susceptibility to infections, photosensitivity without skin cancer, and poor prognosis.3
We observed a preterm collodion male infant with TTD-XPD who died from respiratory failure at 1 year of age. The first diagnosis was ichthyosis congenita but the correct diagnosis was made 1 month
Brusasco A, Restano L, Cambiaghi S, Tadini G. The Typical 'Tiger Tail' Pattern of the Hair Shaft in Trichothiodystrophy May Not Be Evident at Birth. Arch Dermatol. 1997;133(2):249. doi:10.1001/archderm.1997.03890380123028