Seborrheic dermatitis is a greasy, scaly yellow rash that occurs on oily areas of the body like the scalp, face, groin, upper chest and back. It may be mildly itchy. When the scalp is affected, dandruff is seen. As seborrhoeic dermatitis can mimic other scaly red skin conditions such as psoriasis, eczema, fungal infection of the skin and scalp (ringworm), rosacea, lupus and drug rash, it is important to see a dermatologist to correctly diagnose the condition. Treatment is in the form of anti-fungal, anti-inflammatory or keratolytic therapy (removal of scales).
Seborrheic dermatitis also commonly affects young babies. Also known as cradle cap, it causes thick yellow scales on the scalp and eyebrows. It usually clears by 2 months of age.