What Exactly Is Dandruff?
Before we talk about how to prevent and treat dandruff, let's take a moment to talk about what dandruff is (and what it isn't). If you scratch your head vigorously, you'll likely produce a few flakes. That's not dandruff. That's just the normal shedding of skin cells that occurs constantly in all people. With dandruff, this normal process goes awry, causing too much shedding. There are several reasons why this may occur, but the end result is much the same: noticeable flaking of the scalp, often with itching.
Although dandruff might seem like a minor, even comical issue to those who have never had it, in reality, it can be a frustrating, embarrassing, and distressing problem.
There are actually a few different medical conditions that can cause dandruff. The most common cause is seborrheic dermatitis (also known as seborrhea). It is a red, itchy rash that produces patches of white, scaly, flaky skin. It usually occurs on the head (including the scalp) and trunk. When it occurs in babies, it's known as cradle cap.
, another skin condition, can also cause dandruff. Typically, if psoriasis were the cause of your dandruff, you'd have symptoms on other areas of skin, too, not just your scalp.
Sometimes, dandruff is caused by contact dermatitis
, which is basically an allergic reaction to a product you are using such as shampoo, gel, or hair spray. Poor hygiene (in the form of not washing your hair often enough) can be the cause as well.
For many people, the underlying cause of dandruff may be a fungus known as malassezia. This fungus grows on everyone's skin and usually causes no problems. But some people react to it in a way that causes inflammation and dandruff.
Very often, especially in winter, dandruff flakes are simply caused by dry skin. Just as your skin on your body gets flaky in cold, dry weather, the skin of your scalp does too. This type of dandruff is typically quite mild, and many doctors wouldn't even classify it as dandruff at all.