What is dandruff?
Your skin continuously sheds layers of cells, and your scalp sheds more skin cells than other parts of the body. Dandruff is when an excessive amount of larger-than-normal flakes of scalp skin are shed. The flakes stick to the hair shafts, where they may accumulate oil, dust and hair products. These flakes eventually fall on the collars and shoulders of clothes. There may be irritation or itching associated with dandruff.
Symptoms of dandruff
- Clear signs of dandruff are white scales and flakes on the scalp, which may fall onto the shoulders.
- Some irritation or itch may be present.
Causes of dandruff
- The most common cause of dandruff is an overproduction of skin and shedding of dead skin from the scalp.
- Seborrhoeic dermatitis is a red, scaly, itchy rash that causes the scalp to shed skin cells more than is normal. A contributing cause of this condition is overgrowth of a type of yeast known as malassezia. Malassezia yeasts live on most healthy scalps without causing problems, but can cause dandruff when they grow out of control.
What you can do
- Massage your scalp for a few minutes each day to stimulate the circulation and loosen dead skin cells. This can then be followed by vigorous brushing to remove loosened flakes.
- Wash your hair regularly with a medicated anti-dandruff shampoo. Suitable anti-dandruff shampoos include those containing ketoconazole, selenium sulphide, zinc pyrithione, salicylic acid or coal tar. Sometimes changing from one shampoo to another can help if you find a particular shampoo is becoming less effective. Rinse your hair well to eliminate any build-up of hair products. Many people find that regular washing is beneficial; however, some people may find their scalp is irritated by this.
- Oily hair can often benefit from rinsing with fresh lemon juice or cider vinegar diluted in water.
- A dry scalp can often benefit from a warm oil treatment used once a week. Massage olive oil, castor oil or linseed oil into your hair and scalp and warm in a hot towel for at least 10 minutes (preferably a few hours) before washing.
- Avoid excessive use of hair products (including dyes) and change shampoo if one brand is not proving effective. An allergy-free product may work better for you.
- Stress and negative emotions have been known to play a significant part in skin conditions such as dandruff, so relaxation techniques may be helpful.
When to see your doctor
Dandruff is generally considered harmless, but in some cases, dandruff may cause thinning of the hair, and may be stress-related. Severe persistent dandruff may be a symptom of a more serious condition such as eczema, psoriasis or seborrhoeic dermatitis, and you should consult your doctor.
2. DermNet NZ. Seborrhoeic dermatitis (revised 20 Mar 2012). New Zealand Dermatological Society, 2012. Available from: http://www.dermnetnz.org/dermatitis/seborrhoeic-dermatitis.html (accessed 9 September 2012).