Dandruff is a common chronic scalp condition marked by flaking of the skin on your scalp. It isn’t contagious or serious, but it can be embarrassing and sometimes difficult to treat.

The good news is dandruff usually can be controlled. Mild cases of dandruff may need nothing more than daily shampooing with a gentle cleanser. More stubborn cases of dandruff often respond to medicated shampoos.

In addition to regular shampooing, you can take steps to reduce your risk of developing dandruff:

>> 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 worsen existing symptoms.

>> Shampoo often. If you tend to have an oily scalp, daily shampooing 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.

>> Alternative medicine. Small studies have found that tea tree oil can reduce dandruff, but more study is needed. Tea tree oil, which comes 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 may cause allergic reactions in some people.

Dandruff shampoos

When regular shampoos fail, dandruff shampoos you can buy at a drugstore may succeed. But dandruff shampoos aren’t all alike, and you may need to experiment until you find one that works for you.

If you develop itching, stinging, redness or burning from any product, stop using it. If you develop an allergic reaction — such as a rash, hives or difficulty breathing — seek immediate medical attention.

Dandruff shampoos are classified according to the medication they contain:

>> Zinc pyrithione shampoos (such as Head & Shoulders, Jason Dandruff Relief 2 in 1): These contain the antibacterial and antifungal agent zinc pyrithione. This type of shampoo can reduce the fungus on your scalp that can cause dandruff and seborrheic dermatitis.

>> Tar-based shampoos (such as Neutrogena T/Gel): Coal tar, a byproduct of the coal manufacturing process, helps conditions such as dandruff, seborrheic dermatitis and psoriasis. It slows how quickly skin cells on your scalp die and flake off. If you have light-colored hair, this type of shampoo may cause discoloration.

>> Shampoos containing salicylic acid (such as Neutrogena T/Sal). These “scalp scrubs” help eliminate scale, but they may leave your scalp dry, leading to more flaking. Using a conditioner after shampooing can help relieve dryness.

>> Selenium sulfide shampoos (such as Selsun Blue): These shampoos slow your skin cells from dying and may also reduce malassezia. Because they can discolor blond, gray or chemically colored hair, be sure to use them only as directed, and rinse well after shampooing.

>> Ketoconazole shampoos (such as Nizoral): 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 or every other day until your dandruff is controlled, then cut back to two or three times a week, as needed. If one type of shampoo works for a time and then seems to lose its effectiveness, try alternating between two types of dandruff shampoos. Read and follow the directions on each bottle of shampoo you try. Some need to be left on for a few minutes, while others should be immediately rinsed off.

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 treatment with a steroid lotion.