Seborrheic dermatitis is better known as dandruff. This extraordinarily common rash can occur on the face as well as on the scalp.
On the scalp it causes the skin to flake and sometimes to itch. On the face, there is redness and flakiness most commonly in the eyebrows, between the eyes and on the folds by the nose, where it can even spread onto the cheek. It can also cause redness and scaling on the forehead, or the chest.
Seborrheic dermatitis is due to a yeast that is normally present on the body. This yeast likes to overgrow in some individuals, and when it does, it creates an irritation which causes scaling. It is NOT due to dry skin, although many people mistake it for that, and reduce the number of times they shampoo in a week, which actually makes it worse.
The best treatments for seborrheic dermatitis are anti-yeast containing prescriptions such as ciclopirox or ketaconazole shampoo and cream. Sometimes a topical steroid or Elidel is required to keep the inflammation down. In severe cases, sometimes an oral medication that kills yeast is necessary.