Trichorrhexis invaginata

What it means

A type of hair shaft dysmorphology in which the proximal part of the hair shaft overlaps the distal part, showing a bamboo-like appearance. This feature is pathognomic for Netherton syndrome, and can be ascertained by light microscopy.

Mostly, these hairs are fragile, short, and brittle. A longitudinal twist in the hair shaft may be seen, known as a helical hair.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Bamboo hair · Helical hair