A very common, and very annoying, rash.

Seborrheic dermatitis is a common, annoying, scaling rash that sometimes itches. Most commonly it involves the scalp, the eyebrows, eyelid edges, ears, the skin near the nose and skin-folds of the armpits and groin. Sometimes seborrheic dermatitis produces round, scaling patches on the middle of the chest or on the back. Seborrheic dermatitis is believed to be due to an overgrowth of a yeast called Pityrosporum ovale (Malassezia furfur).