Seborrheic dermatitis is a common, chronic or relapsing form of eczema/dermatitis that mainly affects the sebaceous, gland-rich regions of the scalp, face, and trunk . It is a papulosquamous disorder patterned on the sebum-rich areas of the scalp, face (on the sides of the nose, behind the ears, and elsewhere), eyebrows, external ear canals, chest, and back. Seborrheic dermatitis is associated with normal levels of Malassezia but an abnormal immune response.

Seborrheic dermatitis is sometimes a sign of an underlying medical condition. The abnormal immune system activity causes skin cells to grow too rapidly. This causes greasy flakes on your skin. Your doctor may refer to this by its Latin name, pityriasis simplex capillitii .

Seborrheic dermatitis, also known as seborrhea, is a common non-contagious condition of skin areas rich in oil glands (the face, scalp, and upper trunk). Seborrheic dermatitis may affect any hair-bearing area, and the chest is frequently involved. Affected areas may appear greasy and yellowish scales may form on the scalp.

Seborrheic dermatitis is usually not a serious problem. It tends to be chronic and comes and goes for no apparent reason. Treatments can control it and sometimes clear it up completely. The cause of seborrheic dermatitis is unknown but probably involves a variety of factors including:

Seborrheic dermatitis is a common inflammatory skin condition affecting the scalp, face and upper trunk. In infants, seborrheic dermatitis of the scalp is commonly referred to as “cradle cap.” In adolescents and adults, seborrheic dermatitis commonly occurs on the scalp (dandruff). The involved areas may be red and scaly with yellowish or white scales. Rarely, there may be small fluid-filled bumps that become crusted over. The affected areas are usually itchy.

Seborrheic dermatitis is more common in men than women and is more common in people with oily skin. It also appears to have a genetic tendency as it often affects members of the same family. Seborrheic dermatitis is not caused by poor hygiene alone. Other factors are thought to play an important role, including abnormalities in the rate at which skin cells mature, changes in oil production and a yeast (Malassezia) that normally lives on hair follicles. Seborrheic dermatitis is also common in infants and people with AIDS, Parkinson’s disease or depression.

Seborrheic dermatitis is a skin condition that causes an itchy, red rash to form on the skin. The rash usually forms on the scalp and face but can also appear in other areas. Seborrheic dermatitis is also known as dandruff, seborrheic eczema, or seborrheic psoriasis.

There are several things that can cause seborrheic dermatitis including:

• A yeast overgrowth

• Genetics

• Stress

• Medical conditions such as Parkinson’s, AIDS, stroke, or heart attack

• A weak immune system

• Cold weather

The symptoms of seborrheic dermatitis may vary depending on where it appears on the body and how severe it is. Dry, flaky skin is one of the most common symptoms. Other symptoms include:

• White or yellowish flakes on your hair or shoulders (dandruff)

• Redness and itching on your scalp, eyebrows, eyelids, nose creases, or ear folds

• A greasy coating on your hair or scalp

•

Seborrheic dermatitis is a common skin condition that causes inflammation (swelling), flaking, scaling, and itching of the skin. It occurs most often on the scalp and face.

The skin areas affected are where there are many oil glands, including the:

scalp

eyebrows

creases around the nose and mouth

upper chest

It may also affect other areas of the body such as armpits, groin, or under breasts. It is not clear what causes seborrheic dermatitis. It may be linked to several factors, including:

weather conditions (dry cold weather) or climate

hormonal changes caused by puberty, stress, menstrual periods, pregnancy or taking birth control pills

increased oil production in certain people caused by certain drugs such as lithium or psoralen with UVA (PUVA) therapy for psoriasis

Seborrheic dermatitis is a common, chronic or relapsing form of eczema/dermatitis that mainly affects the sebaceous, gland-rich regions of the scalp, face, and trunk .

Seborrheic dermatitis is a clinical diagnosis based on the location and appearance of lesions. There are no laboratory tests for seborrheic dermatitis.

The exact cause of seborrheic dermatitis is unknown, although genes and hormones play a role. Microbial factors may also be involved. Malassezia yeasts are thought to play a role in seborrheic dermatitis. The severity of the condition appears to correlate with the density of Malassezia yeasts on the skin.

Seborrheic dermatitis is a chronic inflammatory skin condition that commonly affects the scalp, face, and trunk. It affects 1%-3% of the general population and up to 11% of African Americans. Dandruff, which is mild seborrheic dermatitis, affects approximately 50% of the adult population. Seborrheic dermatitis is characterized by symptoms that fluctuate in intensity.

Seborrheic dermatitis is thought to be caused by a combination of several factors:

Malassezia yeasts (fungi), specifically M. globosa and M. restricta, that are part of the normal skin flora (normal microorganisms that live on the body). These yeasts break down oils into free fatty acids, which may irritate sensitive skin and cause an inflammatory response.

The following factors may contribute to the development of seborrheic dermatitis:

Abnormalities in cell turnover rate (how fast new cells form and old cells die). New cells form very quickly in areas affected by seborrheic dermatitis. This causes thickening of the stratum corneum (the outermost layer of the epidermis) and flaking or peeling off as new cells rise to the