Hair Dysplasias

The chapter on hair dysplasias discussed various clinical and morphological characteristics of these conditions. It highlighted atypical pili torti, often associated with Menkes’ syndrome, and other dysplasias like pili canaliculi and woolly hair. Pseudomonilethrix was described as a rare autosomal dominant defect causing hair fragility. Trichorrhexis invaginata involved a ballooning and chaliced deformation of the hair shaft. Trichothiodystrophy was noted as a complex syndrome resulting from low sulfur content in hair, leading to specific dysplasia and hair breakage at distal ends, causing trichoptilosis and trichorrhexis nodosa. Loose anagen hair was identified as a dysplasia due to poor adhesion of the hair shaft to the follicle.