Seborrheic dermatitis has one obvious symptom: dandruff. Other symptoms include itching, soreness, red and oily skin, and white or yellow flakes on the scalp. There might also be patches of scales around the hair follicles [source: AAFP]. In infants, seborrheic dermatitis may manifest itself as scaly patches that are thick, yellow, crusty or greasy. Infants may not notice the itchiness, but as they become toddlers, they may complain about the itchiness and soreness [source: Mayo Clinic].
But symptoms aren't just constrained to the scalp. Seborrheic dermatitis can also appear between folds of skin, between the eyebrows, on eyelids, in the creases of the nose, behind the ears, under the arms or in the groin area. People with seborrheic dermatitis also complain of a burning sensation in facial areas [source: Johnson]. Certain factors can worsen symptoms. Many people complain of seborrheic dermatitis more in the winter when there's cold, dry air, and others report worse symptoms when they're stressed. Seborrheic dermatitis is not related to diet, and it isn't contagious [source: Mayo Clinic].
Seborrheic dermatitis may be difficult to distinguish from psoriasis, another skin disease, because they both cause itchy scales. But psoriasis scales are often silver, while scales caused by seborrheic dermatitis are usually yellow or white. And scales from seborrheic dermatitis are attached to the hair shaft, which doesn't occur with psoriasis [source: Mayo Clinic].
Seborrheic dermatitis symptoms can usually be controlled with proper treatment. Read on to learn what treatments are available.