What Is Dandruff?
Also known as seborrheic dermatitis, dandruff is a condition that causes the skin to become scaly and flake off. When it affects the scalp in teenagers and adults, it can be an embarrassing condition where white flakes are visible in the hair and on one's clothing. Most often, dandruff is treated with a dandruff shampoo. Many types using several key ingredients exist.
Shampoos
All dandruff shampoos are created to be applied to the scalp, then left on for a certain period of time so the medicine contained within can take effect. A person should thoroughly apply the shampoo to the hair, ensuring the shampoo reaches the scalp. When this takes place, the medicine contained within the shampoo is able to penetrate the scalp to the hair follicles.
The manner in which the medication then works depends on the active ingredients contained within the shampoo. For example, a zinc pyrithione shampoo (name brands include Head & Shoulders) works to reduce the presence of the fungus pityrosporum on the scalp. While this fungus occurs naturally on all human skin, those with dandruff have it in excess. By reducing the fungus, the shampoo reduces the dandruff. Another antifungal ingredient is ketoconazole (brand name Nizoral).
Another active ingredient is coal tar (brand names include Neutrogena T/Gel). Coal tar slows the process of skin-cell death, thus preventing the skin cells from flaking off as quickly. A shampoo ingredient with similar results is selenium sulfide (brand name Selsun Blue), which can have the adverse effect of discoloring the hair.
Shampoos with salicylic acid (brand name Ionil T) have exfoliating properties to scrub the scalp, ridding it of flakes. However, this action also can cause dryness.
Effects and Use
After leaving a shampoo on for five minutes, you should thoroughly wash the shampoo off. Because many dandruff shampoos have a tendency to be drying, it may be a good idea to condition the hair immediately afterward.
Dandruff shampoos may be used on a daily basis when first treating signs of dandruff, but should be scaled back in use one dandruff is more controlled. This prevents long-term hair dryness. When applied properly, dandruff shampoos should reduce most or all symptoms of dandruff. However, if a person does not see results within several weeks, a doctor should be consulted to see if a stronger shampoo should be applied.
