TRICHORRHEXIS

INVAGINATA

BAMBOO HAIR

Bamboo hair is a distinctive hair shaft abnormality that may occur sporadically, either in normal hair or with other hair shaft abnormalities, or regularly as a marker for Netherton syndrome. The primary defect appears to be abnormal keratinization of the hair shaft in the keratogenous zone, allowing intussusception of the fully keratinized and hard distal shaft into the incompletely keratinized and soft proximal portion of the shaft. This leads to the typical “ball-and-socket” deformity  or, if fracture of the shaft occurs, a golf tee-shaped distal end of the shaft. Netherton syndrome  is an autosomal recessive-inherited disorder consisting of a triad of ichthyosis, atopic diathesis, and trichorrhexis invaginata. Affected hairs are generally short and brittle and may be irregularly distributed over the scalp; this may lead to potential sampling errors on hair shaft evaluation.