methods , systems , and apparatus for hair treatment are disclosed which include applying treatment radiation to a skin treatment area and / or to one or more hairs to deposit energy in one or more hairs so as to modify the structure ). the applied radiation can modify at least a portion of the hair to make the hair less capable of re - entering the skin . specifically , the proposed technique is directed to decreasing stiffness of at least portion of a hair through diminishing its flexural modulus as well as increasing the bend radius of its sharpest point . the methods and apparatus can treat and / or prevent pseudofolliculitis barbae in the treatment area .