Dandruff is the common name for a condition known as seborrheic dermatitis. It is characterized by scaling, redness, itchiness and often white, greasy flakes in the hair and on clothing. It can also involve the eyebrows, behind and in the ears, the nasolabial folds and the beard area. In severe cases the armpits, central chest and groin can be involved as well.
While some believe that when the scalp is flaky and scaly that they should shampoo less, more frequent shampooing with medicated shampoos is often what is needed to calm the scalp and decrease flaking. Shampoos that contain zinc, selenium sulfide, ketoconazole, salicylic acid and tar should be massaged into the scalp and left on for 5 minutes or longer. The medication is for the scalp. After rinsing the shampoo out, it is okay to use another shampoo for the hair if you would like, and conditioner is fine.
Seborrheic dermatitis is not cured, it is controlled. Daily washing of scalp, face and hair bearing areas with medicated shampoos and soaps (ZNP bar is great for the face), can keep the flaking under control. If over the counter products are not enough, several prescription products including shampoos and leave on creams can be prescribed by your dermatologist.