Coudability hairs: a revisited sign of alopecia areata assessed by trichoscopy

We have previously reported several trichoscopic (dermatoscopic) characteristics, such as black dots, 'exclamation-mark' hairs, broken hairs, yellow dots and clustered short vellus hairs as being useful clinical indicators for alopecia areata (AA). 'Coudability hairs', which are normal-looking hairs tapered at the proximal end, have been previously reported as another sign of AA.

To use trichoscopy to evaluate coudability hairs as a clinical indicator for the disease activity of AA and a substitute-marker for the hair-pull test.

Trichoscopic examinations of hair loss and perilesional areas on the scalps of 100 East Asian patients with AA were performed using a dermatoscope. Using Spearman's rank-order correlation coefficient by rank test, we examined the correlations of scores between coudability and AA disease activity, severity or duration and other trichoscopic features, and then evaluated the coudability score as a surrogate-marker for the hair-pull test.

Coudability scores correlated positively with AA disease activity, hair-pull tests, short duration, black dots and exclamation-mark hairs, and correlated negatively with short vellus hairs.

Coudability hairs, more closely perceived by trichoscopy, are useful-markers for disease activity in AA and provide a surrogate-marker for the hair-pull test.