What is Dandruff?

Even if you don't have them, you probably recognize those white flakes on your shoulders and in your hair as dandruff. It's especially common in dry climates and dry winter months, but it can happen anywhere and to almost anyone. Dandruff can be embarrassing, uncomfortable and unsightly.

Dandruff is caused by the rapid release of skin cells, and are observed as skin flakes on the scalp and on the shoulder areas where flakes of skin have fallen. All humans shed skin cells regularly, but people with dandruff shed scalp skin much faster than others, so that the cells clump together and are visible as white flakes. Along with shedding flakes, the scalp can feel itchy and uncomfortable. The medical name for dandruff is pityriasis capitis, and it's the scalp problem doctors see most often.

The doctors at the Mayo Clinic say that dandruff isn't contagious, and basic dandruff usually isn't a serious medical problem. Rather, it's a chronic condition that can be managed. Dandruff can have a number of causes, ranging from dry scalp skin or not washing your hair often enough to eczema or psoriasis.

An article from the physicians at WebMD.com describes two other less-common types of dandruff that may need a doctor's help. One is seborrheic dermatitis. This is a skin disease that causes redness and lesions, or sores, and can occur on other parts of the body besides the scalp. Flakes can be yellowish and greasy, unlike the dry white flakes described above. The other type is believed to be caused by a fungus called Pityrosporum ovale, which occurs in most people but is excessive in some. It causes a skin irritation that makes the skin cells shed even faster. If you scratch too much in either of these cases, you can open the scalp, and that can lead to a serious infection of staph or strep bacteria.

If your dandruff consists of an itchy scalp and unattractive white flakes, find the right shampoo. If not, you may need to see a physician.