Abstract Hair plays a significant role in body image, and its appearance can be changed relatively
easily without resort to surgical procedures. Cosmetics and techniques have therefore
been used to change hair appearance since time immemorial. The cosmetics industry has developed
efficient products that can be used on healthy hair or act on concomitant diseases of the
hair and scalp.
Dyes embellish the hair by bleaching or coloring it briefly, for temporary periods of longer
duration, or permanently, depending on the composition of a dye (oxidative or nonoxidative)
and its degree of penetration of the hair shaft. The dermatologist’s knowledge of dyes, their
use, and their possible side effects (contact eczema, cancer, increased porosity, brittleness)
can extend to an understanding of cosmetic resources that also treat hair and scalp conditions.