L21: Seborrhoeic dermatitis

L21.9: Seborrhoeic dermatitis, unspecified

The precise cause of this skin disorder is unknown. The skin has probably been colonized by fungi. As a result, your skin has become inflamed. The areas of skin that are usually affected are those that produce a lot of sebum and are often hairy. These include the face, upper body and groins, for example.

Certain areas of your skin are very scaly and red. Often, the skin does not itch at all, or only a little.

The rash can get worse in the winter months and with certain illnesses.