So following on from Sassy's Q. What is cradle cap, why do people get it and how do you get rid of it?
H I it is called this in adults and is not
What is seborrhoeic dermatitis and who gets it?
Seborrhoeic dermatitis is a type of skin inflammation. It mainly occurs in young adults and teenagers. About 1 in 25 adults between the ages of 18 and 40 develop this condition. It is more common in men than women. Some babies have a similar condition that usually clears within a few months. (See separate leaflet called 'Seborrhoeic Dermatitis and Cradle Cap in Babies'.) It does not occur in children older than about 8-9 months.
The exact cause is not known. A yeast germ (similar to a fungal germ) called Malassezia furfur
(previously called Pityrosporum ovale
) is involved. However, it is not just a simple skin infection and it is not contagious (you cannot 'catch' this condition from others).
This yeast germ lives in the sebum (oil) of human skin in most adults. In most people it does no harm. But some people seem to 'react' to this germ in some way which causes inflammation.What is the treatment for seborrhoeic dermatitis?
Commonly used treatments include the following.
* An antifungal (anti-yeast) shampoo such as ketoconazole 2% is used to treat the scalp, eyebrows and other hairy areas. This kills the yeast germ and the skin then usually returns to normal. Use the shampoo 2-3 times a week (and use normal shampoo the rest of the time). Leave the shampoo on for about five minutes before rinsing off.
* An antifungal cream is used to treat other areas. Apply the cream to affected areas once or twice daily, depending on the type of cream prescribed.
It often takes 2-4 weeks to completely clear the dandruff or rash. Keep using the treatment for a few days after the dandruff or rash have cleared.
Other treatments which may be used include the following.
* A 'normal' anti-dandruff shampoo that contains zinc pyrithione or coal tar may clear dandruff in mild cases if used regularly.
* A mild steroid cream and/or steroid scalp lotion is sometimes advised for a week or so in addition to an antifungal cream or shampoo. This is used if the skin or scalp is badly inflamed. Steroid creams and lotions dampen inflammation which reduces the redness and itch.
* A scale softener is sometimes advised for the scalp to 'lift the scale' if dandruff is severe. This is in addition to the antifungal shampoo.
* A course of antifungal tablets may be needed if the condition affects many areas of skin, or is not clearing with an antifungal cream.
* Phototherapy (light treatment) with ultraviolet B is sometimes used in severe cases.
The condition goes if the yeast germ is cleared from the skin by the above treatments. However, the sebum is a natural place for the yeast germ to live. In many cases, the number of yeast germs gradually rises again on the skin after finishing a course of treatment. So, in many cases the condition tends to recur some weeks or months after finishing a course of treatment. Each episode can be treated as it occurs. However, if you have frequent episodes you may wish to consider using treatment to prevent the condition from recurring.
How can I prevent seborrhoeic dermatitis from recurring?
Once the symptoms have gone with treatment, the following may help to keep the condition from recurring.
* For the scalp - use an antifungal shampoo such as ketoconazole 2% once every 1-2 weeks. Leave on the scalp for five minutes before rinsing. (Use a normal shampoo at other times.)