What is Dandruff?
Dandruff is a common chronic scalp condition, which is marked by itching and flaking of the skin on your scalp. Although dandruff isn't contagious and is rarely serious, it can be embarrassing and sometimes difficult to treat.
As it is normal for skin cells to die and flake off, a small amount of flaking is normal and in fact quite common. Some people, however, either chronically or as a result of certain triggers, experience an unusually large amount of flaking, which can also be accompanied by redness and irritation. Most cases of dandruff can be easily treated with specialized shampoos.
Symptoms
For most teens and adults, dandruff symptoms are easy to spot: white, oily looking flakes of dead skin that dot your hair and shoulders and an itchy, scaling scalp.
A type of dandruff called cradle cap also can affect babies. 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.
When to see a doctor Most cases of dandruff don't require a doctor's care. But if you're still scratching your head after several weeks of experimenting with over-the-counter (OTC) dandruff shampoos or if your scalp becomes red or swollen, see your doctor or dermatologist. You may have seborrheic dermatitis or another condition that resembles dandruff. Most often, your doctor can diagnose the problem simply by looking at your hair and scalp. |
Causes
The epidermal layer continually replaces itself, cells are pushed outward where they eventually die and flake off. In most people, these flakes of skin are too small to be visible. However, certain conditions cause cell turnover to be unusually rapid, especially in the scalp. For people with dandruff, skin cells may mature and be shed in 2 - 7 days, as opposed to around a month in people without dandruff. The result is that dead skin cells are shed in large, oily clumps, which appear as white or grayish patches on the scalp, skin and clothes.
- Dry skin. Simple dry skin — the kind you get during winter when the air is cold and rooms are overheated — is the most common cause of itchy, flaking skin. Flakes from dry skin are generally smaller and less oily than those from other causes of dandruff.
- Irritated, oily skin (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.
- Not shampooing often enough. If you don't regularly wash your hair, oils and skin cells from your scalp can build up, causing dandruff.
- 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.
- Eczema. If you have eczema on your scalp, it's possible you could develop dandruff.
- Sensitivity to hair care products (contact dermatitis). Sometimes sensitivities to certain hair care products or hair dyes can cause a red, itchy, scaling scalp. Shampooing too often or using too many styling products also may irritate your scalp, causing dandruff.
- A yeast-like fungus (malassezia). 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. This can irritate the skin on your scalp and cause more skin cells to grow. The extra skin cells die and fall off, clumping together with oil from your hair and scalp, making them appear white, flaky and visible in your hair or on your clothes.
Exactly what causes an overgrowth of malassezia isn't known, although having too much oil on your scalp; changes in your hormones; stress; illness; neurological disorders, such as Parkinson's disease; a suppressed immune system; not shampooing often enough; and extra sensitivity to the malassezia fungus may contribute to the development of dandruff.
Treatement
Shampoos use a combination of ingredients to control dandruff. Salicylic acid (used in Sebulex) and coal-tar (used in Tegrin) remove dead skin cells from the scalp and decrease the rate at which these cells are created. Zinc pyrithione (used in Head and Shoulders) kills pityrospora. Selenium sulfide (used in Selsun Blue) achieves the results of both salicylic acid and zinc pyrithione.
Simply increasing usage with normal shampooing will remove flakes.However, elimination of the fungus results in dramatic improvement. Regular shampooing with an anti-fungal product can reduce recurrence.
Soothing preparations may contain Sodium bicarbonate (baking soda), and coal tar based products.
The most common antifungal agents used are Zinc pyrithione, Selenium sulfide and Ketoconazole Other products used include Tea tree oil and Piroctone olamine (Octopirox).
Anti-fungal/anti-dandruff shampoos containing ketoconazole have been shown to be more effective than zinc pyrithione. Although one study has reported selenium sulfide as being the most effective of the tested shampoos at treating dandruff, a later comparative study concluded that ketoconazole was the most effective antifungal agent.
- Zinc pyrithione shampoos (such as Selsun Salon, Head & Shoulders). These contain the antibacterial and antifungal agent zinc pyrithione, which 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 by slowing how quickly skin cells on your scalp die and flake off.
- Shampoos containing salicylic acid (such as 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 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 to 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.
Site Refference
http://www.mayoclinic.com/health/dandruff/DS00456/DSECTION=symptoms
http://en.wikipedia.org/wiki/Dandruff
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