Canestick Lesion of Vellus Hair in Netherton's Syndrome

Netherton's syndrome, a rare congenital ectodermal defect, was characterized by erythematous and scaly skin at birth, progressing to serpiginous scaling on the trunk and extremities, along with lichinified dermatitis and short brittle scalp hair. The diagnostic feature, tricorrhexis invaginata or "bamboo hair defect," was identified in the vellus hair of a 7-year-old boy's scalp, which was initially mistaken for an artifact due to its rarity in literature. This case highlighted the importance of recognizing this hair defect for diagnosing Netherton's syndrome.