Clinical Signs of Hair Damage

The 2015 document outlines the clinical signs of hair damage, which are more evident in the distal parts of long hair and can be worsened by hair diseases. It notes that ethnicity affects susceptibility to damage, with African hair being more prone to mechanical damage and Asian hair being resistant to chemical treatments. Cosmetic procedures contribute to hair damage through the use of harsh chemicals and prolonged exposure. Signs of damage include fragility, loss of shine, dryness, and discoloration, leading to dull, brittle, and lighter-colored hair. Specific types of damage described include trichorrhexis nodosa, trichoptilosis, trichoschisis, trichoclasis, and bubble hair. Hair breakage varies by ethnicity, with African hair showing patchy alopecia and Caucasian/Asian hair exhibiting chemical and thermal damage. Diagnosis involves the tug test, dermoscopy, and cross-section trichometer. The document also discusses matting, tangling, and knotting due to friction, which can be exacerbated by hairstyles or extensions. Additionally, it describes how damaged hair lightens in color, with extreme cases turning green from copper exposure, treatable with chelating shampoos or penicillamine.