History:

A 5-year-old girl presented with hair sparsity on the scalp since infancy. On direct examination of the hair under light microscope a bamboo hair (trichorrhexis invaginata) was seen. Bamboo hair results from intussusception of the hair shaft at the zone where keratinization  begins. The invagination is caused by softness of the cortex in the keratogenous zone.The softness may be caused by inadequate conversion of S-H to S-S proteins in the cortex. The patient with bamboo hair will have nodose ball-and-socket deformities, with the socket forming the proximal and the ball part forming the distal portion of the node along the hair shaft. This type of hair is associated with Netherton syndrome. The bamboo hairs may become normal within a few years. An autosomal recessive mode of inheritance has been suggested, although reported cases involving women far outnumber men.