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The most common causes of dandruff, which appears as flaky skin on the scalp, includes dry skin and washing hair too often or too seldom. In some cases, dandruff may be caused by seborrhoeic dermatitis or psoriasis. Other causes of dandruff include contact dermatitis and malassezia.
Dry skin, which is especially common in colder climates, is usually the issue with dandruff. As with other areas on the body, dry skin tends to become irritated and flaky. When dry skin is the problem, it can usually be rectified by using cooler water to wash the scalp area, cleansing with a moisturizing shampoo, and limiting hair washing to every two to three days.
One of the most typical causes of dandruff is not taking proper care of the scalp. Although dandruff can be caused by dry skin, it can also result from skin that is too oily. Those with especially oily skin may develop dandruff if they do not wash their scalp and hair often enough, just as those with dry skin can develop dandruff by washing too often. In some cases, dandruff may be caused by failing to completely rinse the hair and scalp of shampoo or conditioner, thereby causing irritation and flaking.
Seborrhoeic dermatitis is the clinical term for dandruff, although the word dandruff is often used to describe any number of issues that cause flaking or irritation of the scalp. Seborrhoeic dermatitis is defined as inflamed, greasy skin that produces white or yellow scales. These scales peel or fall off, thus creating dandruff. Although this often occurs on the scalp, it can appear anywhere on the body, especially in areas with hair. It is common for those who experience this skin condition on the scalp to also have issues with their eyebrows or other facial hair. Special shampoos and conditioners can often help to treat this skin condition.
Another of the many causes of dandruff is psoriasis. This skin issue is very similar to seborrhoeic dermatitis; it is often difficult for doctors to tell the difference between the two. In general, psoriasis typically produces thicker, less greasy scales than seborrhoeic dermatitis. People with psoriasis of the scalp often have mild to moderate psoriasis in other areas. As the scales caused by psoriasis begin to fall, they create dandruff on the scalp. Treatment options depend on the severity of the psoriasis and whether it occurs in areas other than the scalp.
Contact dermatitis is one of the most common causes of dandruff and is often relatively easy to treat. This cause of dandruff is the result of an allergic reaction to something that comes in contact with the scalp. The most common culprits are shampoos, conditioners, and hair styling products. In some cases, the detergent used to wash towels may cause contact dermatitis and therefore dandruff. As long as the reaction is not excessively severe, contact dermatitis usually goes away when the use of the aggravating product is discontinued.
In rare cases, malassezia may be the cause of dandruff. This skin condition is the result of a fungus that forces the scalp to produce too many skin cells, thereby increasing shedding. Although the causes of dandruff can vary greatly, they are usually treatable or controllable with the proper lifestyle changes and, if necessary, medication.