Dandruff occurs when your scalp sheds dry patches of skin. You may see these flakes in your hair or on your shoulders. Dandruff can also make your scalp itchy.
It’s a common problem, but dandruff isn’t as simple as it seems. Dandruff can be difficult to define because it is related to seborrheic dermatitis (a form of chronic eczema) and other skin conditions that cause a scaly scalp.
Skin cells growing and dying too quickly are the problem. Why this happens remains unclear. A very common fungus calledmalassezia can cause dandruff. This fungus lives on the scalps of most healthy adults without causing any problems. One theory is that the immune system of a person with dandruff may be overreacting to the fungus.
Dandruff can get worse when you are stressed or sick. Cold, dry winters can trigger or make dandruff worse. Here’s what you need to know.
Signs and Symptoms You Have Dandruff
White patches on the scalp, consisting of loose dead skin in your hair is the most obvious sign of dandruff. Other signs are as follows:
- Oily or dry scales may appear on the scalp.
- Sometimes your scalp feels itchy.
- A person with severe dandruff may notice scaly yellowish to reddish bumps along the hairline.
Causes and Risk Factors of Dandruff
Seborrheic Dermatitis
If you have really bad dandruff, it’s likely a mild case of seborrheic dermatitis (SD), according to the American Osteopathic College of Dermatology.
SD is a form of chronic eczema that affects areas of the body that secrete the most sebum, or oil.
People with oily skin are often more susceptible to dandruff. A yeast called Malassezia globosa feeds on the oils on the scalp. Some people’s bodies perceive the breakdown of these oils as irritation, so the scalp reacts by increasing the rate of skin cell renewal. This can cause dandruff. For those without dandruff, it takes a full month for new skin cells on the scalp to mature, die, and fall off. However, for those with dandruff, this process occurs in just 2 to 7 days.
However, although M. globosa may be a major risk factor for dandruff, researchers have not established a causal relationship.
Dry Skin
Winter air makes your entire skin dry, including your scalp, so dry skin can be the cause of dandruff. If dry skin is causing dandruff, the flakes are usually smaller and less oily than flakes caused by SD. In addition, cold and dry climates can exacerbate SD.
Almost anyone can experience dandruff, but these factors can make you more susceptible.
Contact Dermatitis
Contact dermatitis is skin irritation that occurs due to allergens or irritants, causing a rash that is itchy and may be painful. In cases of dandruff, the reaction occurs on the scalp. According to the American Academy of Dermatology Association, this generally occurs because of hair care products or hair dye.
Shampoo
Some people believe that dandruff will get worse the more frequently you wash your hair, but in reality this is not the case. In fact, not shampooing your hair can make dandruff worse. This causes more oil and dead skin to stick to the scalp, thereby worsening dandruff. Medicated shampoo can help.
Over-the-counter shampoos are available at most drug or grocery stores. Shampoos that contain ketoconazole, selenium sulfide or zinc are the best for treating dandruff. You can also use a dandruff conditioner if your hair is more brittle than normal.
Other Skin Conditions
Skin conditions such as eczema and psoriasis can also appear on the scalp, causing dandruff. Depending on the severity of this skin condition, over-the-counter hair care products may not be able to resolve the problem. Ask your dermatologist before trying something new. The wrong product can worsen skin conditions like eczema and psoriasis.
Dandruff is harmless. But it’s quite embarrassing and itchy. Dandruff isn’t actually about your hair, or how often you shampoo it. Instead, it’s about the skin on your scalp.
