DanDruff

Dandruff is the  shedding of the  scalp’s  epidermal cells,  something that  affects most  people  in various  degrees. The  skin of the scalp constantly sheds, but  when the  scalp’s dead  cells shed  at a rapid  rate, large grey-white clumps appear  on the top of the scalp and become visible. Manufacturers of shampoos and conditioners have produced an array  of safe and  unsafe over-the-counter products that  have been  sold under both the banner of beauty  and  medicine to eliminate or prevent dandruff.

Mild forms  of dandruff are the  most  common and  are easily treated by washing  the  hair  more  frequently, but  more  serious conditions also  produce similar kinds  of itching and flakes. Seborrheic dermatitis, for example,  is often  difficult to distinguish from  dandruff, but  it is treated with a prescription drug.  People  with oily scalps  more  easily produce yeast  and  thus  tend  to suffer  most  from  seborrheic  dermatitis, dandruff, and  Pityrosporum ovale, which  leads  to scalp  irritation and scaling. The  yeast is rare among children, but its prevalence tends  to increase with age. Males are also more  likely than females to experience dandruff, probably because of the  yet-unclear effect of androgen hormones. More  severe  dandruff may also indicate a fungal  infection or another dermatological disorder such  as psoriasis, a skin disease that must be treated by a dermatologist and that can occur on other parts  of the body than the scalp.

Treatments

For individuals who do not find relief from shampooing, drug  products may help. Mild dandruff is typically treated with popular over-the-counter shampoos such as Selsun Blue or the  aptly named Head  and  Shoulders. In 1990,  the  U.S.  Food and  Drug Administration (FDA)  banned 27  unsafe or  ineffective  ingredients commonly found in dandruff shampoos. There are currently five ingredients that the  FDA  has  determined to  be safe and  effective,  including coal  tar,  pyrithione zinc, sulfur, selenium sulfide,  and  salicylic acid. However, not  all problems with these  ingredients have  been  eliminated. Coal  tar  not  only  leaves an  orange tint that  often  lingers  after the shampoo has been  used,  especially  in light-colored or dyed  hair,  but  one  form  of treated bituminous coal increases sensitivity  to sunlight, and long-term use is associated with skin cancer. Products that  include coal tar advise its use only for a short-term basis.