Skin Care - Dandruff

Introduction

If dandruff is the only thing standing between you and a closet full of basic black, you're not alone. Many people have this chronic scalp disorder, which is marked by itching and excessive flaking of the scalp. Although dandruff isn't contagious and is rarely serious, it can be embarrassing and surprisingly persistent.

The good news is that dandruff can usually be controlled. Mild cases of dandruff may need nothing more than daily shampooing with a gentle cleanser. And stubborn flakes often respond to medicated shampoos. What's more, researchers have identified a yeast-like fungus that may cause or aggravate dandruff, a discovery that may lead to better treatments.

Signs and symptoms

For most people, the signs and symptoms of dandruff are unmistakable: white, oily looking flakes of dead skin that dot your hair and shoulders and an itchy, scaling scalp. But it's not quite that simple — many conditions cause excessive skin scaling, including:

• Dry skin. Simple dry skin — the kind you get in winter when the air is cold and rooms are overheated — is by far the most common cause of itchy, flaking skin. But flakes from dry skin are generally smaller and less oily than those caused by dandruff.

• Seborrheic dermatitis. This condition, a frequent cause of dandruff, is marked by red, greasy skin covered with flaky white or yellow scales. Seborrheic dermatitis affects not only your scalp but also other areas rich in oil glands, such as your eyebrows, the sides of your nose and the backs of your ears, your breastbone, your groin area, and sometimes your armpits.

• Psoriasis. This skin disorder causes an accumulation of dead skin cells that form thick silvery scales. Psoriasis commonly occurs on your knees, elbows and trunk, but it can also affect your scalp.

• Cradle cap (seborrheic dermatitis of the scalp). This disorder, which causes a scaling, crusty scalp, is most common in newborns, but it can occur anytime during infancy. Although it can be alarming for parents, cradle cap isn't dangerous and usually clears up on its own by the time a baby is a year old.

• Contact dermatitis. Sometimes sensitivities to certain hair-care products or hair dyes can cause a red, itchy, scaling scalp.
  

Causes

At one time or another, dandruff causes have been attributed to dry skin, oily skin, shampooing too often or not often enough, a poor diet, stress, and the use of too many fancy styling products. Although some of these factors may exacerbate or contribute to scalp flaking, the real culprit may be a fat-eating, yeast-like fungus called malassezia, formerly known as pityrosporum.

Malassezia lives on the scalps of most healthy adults without causing problems. But sometimes it grows out of control, feeding on the oils secreted by your hair follicles and causing irritation that leads to increased cell turnover. The result is a large number of dead skin cells. As the cells fall off, they tend to clump together with oil from your hair and scalp, making them appear white, flaky and all too visible.

Exactly what causes an overgrowth of these organisms isn't known, although increased oil production; hormonal fluctuations; stress; illness; neurological disorders, such as Parkinson's disease; a suppressed immune system; infrequent shampooing and extra sensitivity to the malassezia fungus may contribute to the development of dandruff.

Risk factors

Almost any adult is a candidate for dandruff, but certain factors can make you more susceptible:

• Age. Dandruff usually begins in young adulthood and continues through middle age. That doesn't mean older adults don't get dandruff, however. For some people, the problem can be lifelong.

• Sex. Because more men than women have dandruff, some researchers think male hormones may play a role in dandruff. Men also have larger sebaceous glands that produce an oil called sebum.

• Oily hair and scalp. Malassezia feeds on oils in your scalp. For that reason, having excessively oily skin and hair makes you more prone to dandruff.

• Certain illnesses. For reasons that aren't clear, adults with neurological diseases, such as Parkinson's disease, are more likely to develop seborrheic dermatitis and dandruff. So are people recovering from stressful conditions, particularly heart attack and stroke, and those with compromised immune systems.

Treatment

Dandruff is a chronic condition that can almost always be controlled, but dandruff treatment may take a little patience and persistence. In general, mild scaling can often be helped by daily cleansing with a gentle shampoo to reduce oiliness and cell buildup.

When regular shampoos fail, OTC dandruff shampoos may succeed. But dandruff shampoos aren't all alike, and you may need to experiment until you find one that works best for you.

Dandruff shampoos are classified according to their active ingredient:

• Zinc pyrithione shampoos (Selsun Salon, Head & Shoulders). These contain the antibacterial and antifungal agent zinc pyrithione, which has been shown to reduce the fungus that causes dandruff and seborrheic dermatitis.
• Tar-based shampoos (Neutrogena T/Gel). Coal tar, a byproduct of the coal manufacturing process, helps conditions such as dandruff, seborrheic dermatitis and psoriasis by slowing cell turnover.
• Shampoos containing salicylic acid (Ionil T). These "scalp scrubs" help eliminate scale, but they may leave your scalp dry, leading to more flaking. Using a conditioner after shampooing can help counter dryness.
• Selenium sulfide shampoos (Selsun Blue). These shampoos help prevent cell turnover and may also reduce the number of malassezia. Because they can discolor blonde, gray or chemically colored hair, be sure to use them only as directed and to rinse well after shampooing.
• Ketoconazole shampoos (Nizoral). The newest addition to the dandruff armamentarium, ketoconazole is a broad-spectrum antifungal agent that may work when other shampoos fail. It's available over-the-counter as well as by prescription.

Try using one of these shampoos daily until your dandruff is controlled, then cut back to two or three times a week. If one type of shampoo works for a time and then seems to lose its effectiveness, try alternating between two types of dandruff shampoos. Be sure to leave the shampoo on for at least five minutes — this allows the ingredients time to work.
If you've shampooed faithfully for several weeks and there's still a dusting of dandruff on your shoulders, talk to your doctor or dermatologist. You may need a prescription- strength shampoo or more aggressive treatment with a steroid lotion.

Self-care

You can't prevent dandruff, but you can take steps to reduce your risk:
Learn to manage stress. Stress affects your overall health, making you susceptible to a number of conditions and diseases. It can even help trigger dandruff or exacerbate existing symptoms.
Shampoo often. If you tend to have an oily scalp, daily shampooing to remove the excess oil may help prevent dandruff.

Cut back on styling products. Hair sprays, styling gels, mousses and hair waxes can all build up on your hair and scalp, making them oilier.

Eat a healthy diet. A diet that provides enough zinc, B vitamins and essential fatty acid may help prevent dandruff.

Get a little sun. Sunlight may be good for dandruff. But because exposure to ultraviolet light damages your skin and increases your risk of skin cancer, don't sunbathe. Instead, just spend a little time outdoors. And be sure to wear sunscreen on your face and body.

Complementary and alternative medicine

While there are many purported home remedies for dandruff, one therapy that seems to be effective is daily shampooing with tea tree oil. Tea tree oil, which is extracted from the leaves of the Australian tea tree (Melaleuca alternifolia) , has been used for centuries as an antiseptic, antibiotic and antifungal agent. It's now included in a number of shampoos found in natural foods stores. The oil is generally well tolerated but may cause allergic reactions in some people.