University Health Service

What is dandruff?

Dandruff (also known as seborrheic dermatitis) is the excess shedding of the top layer of the skin on the scalp, eyebrows or along the sides of the nose. This top layer of skin consists of dead cells, which protect the more fragile cells below. It is normal for these to be shed or rubbed off because the body is constantly producing new cells that simply move up to replace older ones. However, in dandruff, larger "scales" are shed at an increased rate.

Dandruff is primarily an aesthetic problem, which many people find unattractive or embarrassing. There is nothing medically serious about it. It will not lead to baldness, and it is not contagious. Itching may accompany dandruff. Usually hair follicles (roots of the hair shafts) do not become infected

Dandruff occurs as frequently in men as in women. It tends to increase in adolescence and young adulthood and decrease thereafter. Those who have acne or oily skin also tend to have more problems with dandruff.

Dandruff usually improves during the summer months, unless the weather is exceptionally hot and humid. Exposure to natural sunlight and a reduction in stress may help to control it.


The cause of dandruff is unclear. It may be related to hormone production since it commonly begins during adolescence. It may be worsened by sensitivity to a yeast micro-organism which is normally on the scalp and skin.


Type of shampoo: Frequent washing with a regular shampoo is the most important treatment for dandruff. Use a regular shampoo to remove the scales as quickly as they form. In addition, the detergents in the shampoo will cause smaller, less visible flakes to shed. Some people mistakenly think that dandruff is caused by a dry scalp that will improve by shampooing infrequently or by applying oily substances to the scalp. This will actually aggravate the condition by preventing the shedding of cells.

If frequent washing with a regular shampoo does not control dandruff, try a dandruff shampoo. Choose products with effective ingredients (check labels):

  • Very effective: Nizoral 1% (active ingredient: ketoconazole) is an antifungal shampoo that helps reduce the number of yeast micro-organisms present on the scalp
  • Moderately effective: salicylic acid and sulfur (selenium sulfide)

Dermatologists recommend alternating a regular shampoo with an antifungal shampoo when dandruff appears. Dandruff shampoos may need to be used routinely to control dandruff. As symptoms improve, you may use dandruff shampoos less frequently.

Hair washing method is important in treating dandruff. Lather the hair twice and on the second lather, leave the shampoo on the hair for five minutes (or as directed on the shampoo label) before rinsing to give the medicine time to work properly.

The frequency of shampooing necessary to control dandruff varies from person to person. Some need to shampoo twice a week, others more frequently, even daily.

Many people forget that the scalp as well as the hair needs to be shampooed. Massaging the scalp to promote circulation may be beneficial, but scrubbing the scalp may be harmful.

Seek medical help if:

  • Itching associated with dandruff increases
  • Using a dandruff shampoo fails to control the problem adequately
  • Inflammation (redness, swelling, severe scaling) occurs on the scalp or other parts of the body

For more information:

Schedule an Appointment: Appointments are required for most medical services, however options are available for urgent concerns.

Nurse Advice by Phone is available day and night, which may save a trip to UHS, the ER or an urgent care facility.

The UHS Pharmacy sells antifungal shampoo Nizoral 1% (active ingredient: ketoconazole).