Seborrhoeic (pronounced seb-or-A-ik) simply means that the rash appears in those areas of the skin with large numbers of grease (sebaceous) glands, such as the scalp and sides of the nose.
Seborrhoeic dermatitis in adults
Adult seborrhoeic dermatitis ( also called seborrhoeic eczema) usually starts on the scalp as dandruff that can progress to redness, irritation and increased scaling, which becomes seborrhoeic eczema. As the scalp becomes inflamed, the eczema may spread onto the face and neck.
Eyebrows, temples, folds at the sides of the nose, and neck are often affected – the area looks red and sheds small white flakes of skin. Seborrhoeic dermatitis can be particularly bad behind the ears – larger, greasy scales stick to the skin and surrounding hair, making the area look thickly crusted. The ear folds and canal may also be affected, causing irritation inside the ear, which is called ear eczema.
Seborrhoeic dermatitis often occurs only on the scalp and face, but it can extend to the centres of the chest and back, especially in men. Other areas which can also be affected are the armpits, under the breasts, groin and between the buttocks and genitals.
The role of pityrosporum ovale
The cause of seborrhoeic eczema is not entirely clear. However, it has come to light that a yeast called pityrosporum ovale (also known as malassezia furfur) is found on the skin of people with seborrhoeic dermatitis. At present it is not clear if this yeast is the sole cause or merely a contributing factor to seborrhoeic dermatitis however it thrives in areas of the body where there are increased numbers of sebaceous glands.
Unfortunately, seborrhoeic dermatitis does tend to return at intervals, especially when treatment is stopped. With treatment the condition can be successfully controlled in most cases so that the skin and scalp are comfortable much of the time.
What to do next? Find out about treatment
You can find out about the range of treatments options for different types of eczema in our comprehensive Treatment area of the website.You wil also find out more about seborrhoeic dermatitis in the National Eczema Society Fact sheet which you can download from the related documents to the right of the page.