While everybody frets from time to time about bad hair days, people with dandruff problems have even more to fret about–an uncomfortable, itchy scalp and flakes of dried skin visible throughout their hair, and, often, on their clothes. If you’re cursed with dandruff, the problem could be caused by a number of factors, including medical conditions that affect the scalp, allergies, shampooing too often or too little, and dry skin.
There are four main medical conditions or problems that can cause dandruff: psoriasis, eczema, seborrheic dermatitis and malassezia, a fungal infection located on the scalp.
Most people who suffer from psoriasis or eczema experience aspects characteristic of those skin disorders, such as rash-like clumps of dead skin, on various parts of their body. When the rashes occur on the scalp, the dead skin flakes off as dandruff.
The skin disorder seborrheic dermatitis–known as “cradle cap” when it affects infants–causes greasy, red blotches covered with yellow or white scale-like bits of skin to develop on the scalp. Like psoriasis and eczema, dandruff occurs when the scaly skin flakes off.
Although the fungus malassezia is a natural inhabitant of most people’s scalps, it can sometimes spread more rapidly than normal, causing a sharp upswing in the turnover of scalp skin cells. The excess dead cells slough off and become visible as dandruff.
Another common cause of dandruff is an allergic reaction to a hair product. This reaction could be caused by your shampoo, conditioner, gel, hairspray, mousse, hair dye or any other product that comes into regular contact with your scalp. If you are allergic to the product, your scalp will react by becoming itchy, red and scaly with patches of dried, dead skin that flake off as dandruff.
Dandruff can be caused by shampooing too much or too seldom. If you shampoo excessively, the repeated contact with hair products–particularly if they contain harsh chemicals–can irritate your scalp, resulting in an increase in dead skin cells. However, shampooing not often enough holds its own dangers; in this case, dandruff can be caused by a build up of hair oils and skin cells that haven’t been washed out regularly.
Neurological problems such as stress and disorders like Parkinson’s disease may also result in the development of dandruff. While the causes aren’t specifically known, according to the Mayo Clinic, it is thought that neurological stressors and conditions can change your scalp’s ability to resist an overgrowth of dandruff-causing fungus like malassezia.
Other factors that can contribute to the development of dandruff include your diet and hair-brushing habits. Diets low in vitamins and minerals such as vitamin B and zinc can result in dandruff from unhealthy scalp skin. Additionally, when hair brushing isn’t done on a regular basis, dead skin cells can build up on the scalp and flake off later as dandruff.
The most common cause of dandruff, however, is simply dry skin. When the scalp becomes too dry, the skin gets itchy and flakes off.