Generalized trichorrhexis nodosa.

A case of generalized trichorrhexis nodosa is described in a man. Electron histochemical studies showed abnormal staining consistent with a definite disorder in the formation of alpha-keratin chains within the globular matrix of the hair cortex with respect to cystine; keratin amino-acid analysis also revealed low cystine. This cortical change, together with multiple vacuoles found in the endocuticle, are evidently the intrinsic defects which allow relatively trivial chemical and physical trauma to cause trichorrhexis nodosa.