Seborrheic dermatitis is a common inflammatory disease of the skin characterized by scaly lesions usually on the scalp, hairline, and face.
Seborrheic dermatitis appears as red, inflamed skin covered by greasy or dry scales that may be white, yellowish, or gray. It can effect the scalp, eyebrows, forehead, face, folds around the nose and ears, the chest, armpits (axilla), and groin. Dandruff and cradle cap are mild forms of seborrheic dermatitis, and appear as fine white scales without inflammation.
Causes and symptoms
The cause of seborrheic dermatitis is unclear, though it is has been linked to genetic or environmental factors. Pityrosporum ovale, a species of yeast normally found in hair follicles, has been proposed as one possible causative factor. A high fat diet and alcohol ingestion are thought to play some role. Other possible risk factors include:
stress and fatigue
weather extremes (e. g. hot, humid weather or cold, dry weather)
Mild forms of the disorder may be asymptomatic. Symptoms also disappear and reappear, and vary in intensity over time. When scaling is present, it may be accompanied by itching that can lead to secondary infection.
The diagnosis of seborrheic dermatitis is based on assessment of symptoms, accompanied by consideration of medical history.
Kathleen D. Wright RN, The Gale Group Inc., Gale, Detroit,