What Is Dandruff?

Dandruff is a common, non-contagious skin condition of the scalp that is characterized by dry or greasy scales of skin that flake off the scalp.

Dandruff is frequently the result of mild seborrheic dermatitis, a condition that causes skin to become red, itchy and covered with white or yellow scales. Seborrheic dermatitis is most likely to occur where the skin has the most oil glands: on the scalp, eyebrows, nose, chest and groin. In infants, the condition is known as cradle cap, as it usually affects just the head.

Dandruff can occur at any age, but it’s most common in newborns (cradle cap) and young adults. When it begins in adolescence, it often lasts many years.

Signs and Symptoms of Dandruff

The main symptom of dandruff is patches of grey or white flakes of dead skin in the hair or that often fall on the back of the neck or shoulders.

When associated with seborrheic dermatitis, the scalp may also be:

  • Itchy
  • Covered in patches of yellow scales or crust
  • Bumpy or cracked
  • Greasy
  • Tender and inflamed

Mild seborrheic dermatitis can also affect the skin of the nose, ears, upper chest, eyebrows and beard area.

Causes of Dandruff

The most common cause of dandruff is seborrheic dermatitis. The exact cause of seborrheic dermatitis is unknown, but it is related to excess oil production. It may also be related to the yeast malassezia, which lives on human skin.

Other causes of dandruff include:

  • Infrequent shampooing, which leads to a buildup of dead skin cells
  • Dry skin, which is why dandruff is worse in the winter months
  • Oily irritated skin
  • Contact dermatitis caused by sensitivity to dyes and hair care products

Dandruff Treatments

Generally, dandruff can be controlled with frequent shampooing and by using medicated shampoos. If over-the-counter medicated shampoos aren’t effective, your physician may select a prescription-strength shampoo.

These shampoos may contain:

  • Pyrithione zinc: This is an antibacterial and antifungal medication.
  • Salicylic acid: This helps the rid the scalp of scaling.
  • Selenium sulfide: This also slows the death of skin cells and fights fungal infection.
  • Tar: This slows the death and shedding of skin cells.
  • Tea tree oil: Shampoos containing this oil may have an antibiotic and antifungal effect.
  • Ketoconazole: This is a prescription-strength antifungal agent that kills yeast.

Seborrheic dermatitis that’s not on the scalp can be treated with corticosteroid and antifungal creams and ointments.