Seborrhoeic dermatitis, sometimes inaccurately referred to as seborrhoea, is a long-term skin disorder. Symptoms include red, scaly, greasy, itchy, and inflamed skin. Areas of the skin rich in oil-producing glands are often affected including the scalp, face, and chest. It can result in social or self-esteem problems. In babies, when the scalp is primarily involved, it is called cradle cap. Dandruff is a milder form of the condition without inflammation.
The cause is unclear but believed to involve a number of genetic and environmental factors. Risk factors include poor immune function, Parkinson's disease, and alcoholic pancreatitis. The condition may worsen with stress or during the winter. The Malassezia yeast is believed to play a role. It is not a result of poor hygiene, but using anti-dandruff shampoo (on the scalp or skin) can help. Diagnosis is typically based on the symptoms. The condition is not contagious.
The typical treatment is antifungal cream and anti-inflammatory agents. Specifically, ketoconazole or ciclopirox are effective. It is unclear if other antifungals, such as miconazole, are equally effective as they have been poorly studied. Other options may include salicylic acid, coal tar, benzoyl peroxide, and phototherapy.
The condition is most common in infants within the first 3 months or in adults aged 30 to 70 years. In adults between 1% and 10% of people are affected. Males are more often affected than females. Up to 70% of babies may be affected at some point in time.
Seborrhoeic dermatitis' symptoms appear gradually, and usually the first signs are flaky skin and scalp. Symptoms occur most commonly anywhere on the skin of the scalp, behind the ears, on the face, and in areas where the skin folds. Flakes may be yellow, white or grayish. Redness and flaking may also occur on the skin near the eyelashes, on the forehead, around the sides of the nose, on the chest, and on the upper back.
In more severe cases, yellowish to reddish scaly pimples appear along the hairline, behind the ears, in the ear canal, on the eyebrows, on the bridge of the nose, around the nose, on the chest, and on the upper back.