Dandruff: Diagnosis and Treatment

Patient Expert

Reader: I think I have dandruff but I've heard that it can be misdiagnosed. How do I know it's just dandruff and what's the most effective way to deal with it?

The debate over the safety of dandruff shampoos is still unsettled, but it doesn't mean you have to give up on over-the-counter treatments.

Dandruff is a fairly common affliction characterized by itchiness and flaking of the skin on the scalp. It's not a serious issue but it can cause some social embarrassment and discomfort. While there are various explanations regarding why we get dandruff, the newest theory is that dandruff is caused by the proliferation of certain types of fungus-called Malassezia globosa-that live on the scalp.

Malassezia globosa usually exist on the surface of adult scalps, many of whom are unaffected. The fungus subsists on sebum secretions from the oil glands in our skin by secreting enzymes to break down the sebum. A byproduct of this process is oleic acid, which can penetrate the dead layer of skin and cause irritation and a heightened rate of cell turnover. As skin cells fall off at a faster rate, they can clump together, causing them to appear as white flakes.

Dandruff tends to affect men more than women and also tends to be a more common problem for people with oily hair. In addition, it seems to affect those who suffer from high levels of stress or neurological illnesses such as Parkinson's disease.

Psoriasis and seborrheic dermatitis can both be mistaken for dandruff. Unlike dandruff, however, both of these issues can affect other areas of the body. If the condition is limited to your scalp, chances are your problem is dandruff. If you experience red, itchy, flaky patches on other areas of the body, see your dermatologist to rule out other conditions.

Dandruff is simple enough to treat at home. At best, simply shampooing on a daily basis can relieve the buildup of sebum and limit the occurrence of dandruff. If your case is more persistent, take steps to alleviate stress and try a medicated anti-dandruff shampoo.

There are five different types of anti-dandruff shampoos on the market today. Zinc pyrithione and selenium sulfide (the active ingredients in Head & Shoulders and** Selsun Blue**, respectively) are antifungal and antibacterial agents. Another anti-fungal agent called ketoconazole has traditionally been used to treat athlete's foot, but can now be found in Nizoral, an over-the-counter dandruff treatment. Finally, Neutrogena's T-Gel line features coal tar shampoo, which was used in the past to kill head lice and can be effective at treating both dandruff and seborrheic dermatitis.

If your scalp doesn't improve, it's possible you may be using a hair care product that causes skin sensitivity. Some hair dyes and styling products can cause minor allergic reactions, leading to red, flaky skin. Another option is a tea tree oil shampoo. Tea tree oil is touted as a holistic antiseptic and antibacterial agent. Unfortunately, tea tree oil is also known to cause allergic reactions in some people, so patch test the product first before using it regularly.