Trichorrhexis nodosa.

Abstract

Inherited, generalized trichorrhexis nodosa (TN) is a rare disease. It starts in the first years and is associated to metabolic disorders such as argininosuccinic aciduria (5) or other inherited disorders such as monilethrix and pili torti (2). Acquired TN is a more frequent disorder. It is a peculiar response of the shaft of the hair to physical and chemical traumas, such as rubbing (1), too hot hairdryer, dyeing, permanent and brightening solutions. Seasonal recurrences have been associated to prolonged sun exposure, repeated sea bathing and subsequent brushing (4).
In the literature there are two types of acquired TN as follows: proximal TN in Negroes, with hair not growing and breaking near the scalp, and distal TN, which is typical of Caucasian and Asian people. A defect in the synthesis of alpha-keratins has been shown in some subjects with acquired TN following even trivial traumas (3).