ABSTRACT
Hair shaft disorders can be congenital or acquired, the latter most commonly caused by mechanical, physical or chemical traumas.
Congenital hair shaft disorders are usually evident from birth or the first months of life. The abnormalities are usually limited to the scalp, but may involve other terminal hair and rarely body hair. Congenital hair shaft disorders may be classified into two main groups:
1. Hair shaft disorders causing increased fragility and therefore hair breakage with patchy or diffuse alopecia.
