What is the technical term for knotted hair?

• A. Trichotillomania
• B. Trichorrhexis nodosa
• C. Monilethrix
• D. Trichorrhexis lamellosa

Answer: (B)

The term for knotted hair is trichorrhexis nodosa. This describes a structural defect of the hair shaft where nodes or knots form along the strand due to weakness in the cortex, causing the hair to fray and break easily at those knot-like points. Clinically, you may see short, broken fibers and a knotted appearance along the shaft, and damage can be from chemical processing, mechanical stress, or genetic factors.

This is distinct from other options: trichotillomania is a behavioral condition involving hair pulling rather than a shaft defect; monilethrix produces a beaded, regular alternation of thick and thin segments along the hair; and trichorrhexis lamellosa features lamellae or plate-like splits along the shaft rather than distinct knots.