Seborrheic Dermatitis – Dandruff


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Seborrheic dermatitis is a common, harmless scaly rash which most commonly affects the face and scalp. It can also be seen in the midchest, upper back, underarms, groin, eyelid margins (blepharitis) and ears. Common facial areas involved are the sides of the nose and mouth, eyebrows, forehead and, in men, the mustache, beard, and sideburn areas. Both genetic and environmental factors influence the course of the condition, and patients undergo periods of remissions and exacerbations.  It is not contagious or related to diet but may be aggravated by stress, fatigue, decreased health, illness, neurologic disorders, and infrequent shampooing and cleansing of scalp.  The extent of involvement among people can vary. When the condition is mild, patients often complain of itchy “dry skin” on their face or scalp. When it is severe, seborrheic dermatitis can be extremely itchy and irritated. If a person scratches the area, an open sore can develop leading to a bacterial (e.g., staph) infection requiring antibiotic treatment.

Though this commonly occurs in adults, there is an infant form that usually resolves before one year of age. When affecting infants, commonly affected areas are the scalp and diaper area, although anywhere on the skin may be involved.

The term “dandruff” usually refers to the noninflamed form of seborrheic dermatitis.

Seborrheic dermatitis is thought to be caused by a “yeast-like” organism (Malassezia) that is a normal inhabitant of skin. When a person’s skin becomes irritated by this yeast, it leads to the development of the characteristic scaly, itchy rash.

Treatment of seborrheic dermatitis is directed at decreasing the amount of yeast on the skin and quieting down the irritation and inflammation. Treatment options include medicated shampoos containing  anti-yeast preparations, salicyclic acid, tar, and zinc. Topical steroids and topical anti-yeast creams may be prescribed. Most cases can be adequately controlled but there is no permanent cure. Once the rash has resolved, maintenance treatment is usually required to keep the condition under control.

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