SEBORRHEIC DERMATITIS OVERVIEW

Seborrheic dermatitis is an inflammatory condition in which the skin overproduces skin cells and sebum, the skin's natural oil. Seborrheic dermatitis usually occurs in areas of the body that have many oil-producing glands, including the scalp, face, upper chest, and back. Dandruff is a mild form of seborrheic dermatitis. It is also common during infancy; this is called cradle cap. Cradle cap usually resolves by eight to 12 months of age.

This topic discusses the symptoms and treatment of seborrheic dermatitis in infants and adults. Other types of dermatitis are discussed separately. (See "Patient information: Atopic dermatitis (eczema)" and "Patient information: Contact dermatitis (including latex dermatitis)".)

SEBORRHEIC DERMATITIS CAUSES

The cause of seborrheic dermatitis is not completely clear. It is clear that an overgrowth of a normal skin fungus (yeast) occurs with this condition. It is not clear whether the fungus causes the flaking and redness or the increased flaking allows overgrowth of the fungus.

Symptoms may come and go, and may be worse during particular seasons (eg, during cold weather). Outbreaks can also occur during periods of stress, hormonal changes, or illness. Certain neurologic conditions, such as Parkinson disease, may increase the risk of developing seborrheic dermatitis. (See "Patient information: Parkinson disease symptoms and diagnosis".)

SEBORRHEIC DERMATITIS SYMPTOMS

Infants — In infants, seborrheic dermatitis can cause a condition known as cradle cap. This causes redness and greasy scales, most commonly on the scalp, but also on the face, ears, neck, and in the diaper area (picture 1). Unlike in adults, seborrheic dermatitis does not usually cause itching in infants.

The condition usually resolves without treatment in weeks to months, although treatment may be used if needed. (See 'Infant treatment' below.)

Adults — The symptoms of seborrheic dermatitis in adults include redness, greasy scaly patches, and itching of the affected skin.

It usually affects skin that contains many oil glands, including the scalp and face; dandruff of the scalp is a mild form of seborrheic dermatitis. It can also occur on the ears, eyebrows, the bridge and sides of the nose, in the crease between the nose and lip, and occasionally in the groin area (picture 2). It can affect the chest, upper back, armpits, and pubic area. In men, seborrheic dermatitis is usually worse on the skin beneath mustaches and beards.

SEBORRHEIC DERMATITIS DIAGNOSIS

There is no specific test for diagnosing seborrheic dermatitis. The diagnosis is usually based upon a person's history and physical examination. In rare cases, a skin biopsy (removing a small sample of skin) may be necessary to confirm the diagnosis or rule out other conditions that mimic seborrheic dermatitis.

SEBORRHEIC DERMATITIS TREATMENT

The symptoms of seborrheic dermatitis can be effectively controlled with a combination of self-care measures and drug therapy.

Infant treatment — Although cradle cap usually resolves without treatment, it may require treatment in some cases. Suggestions for treatment include:

• Shampoo frequently with baby shampoo and gently remove scaly skin with a soft brush (eg, a soft toothbrush) or fine-tooth comb after shampooing.
• Apply a small amount of an emollient (white petroleum jelly, vegetable oil, mineral oil, baby oil) to the scalp (overnight, if necessary) to loosen the scaly patches, followed by gentle scalp massage with a soft brush (to lift the scale), then shampoo with a nonmedicated baby shampoo.

Medicated over-the-counter shampoos for cradle cap may be too irritating for the baby's scalp and can worsen inflammation.

If seborrheic dermatitis persists despite these measures, additional treatment with a mild topical glucocorticoid may be recommended; a healthcare provider should be consulted before treatment.

Adult treatment

Scalp treatments — Shampooing with an antiseborrheic shampoo can help to control the itching and scaling of dandruff. The shampoos work by preventing the build-up of skin scales. For best results, the shampoo should be left in place for five to 10 minutes before rinsing. The shampoo should be rinsed out of the hair completely.

Several types of antiseborrheic shampoos are available, with the main difference between them being the active ingredient designed to treat the inflammation or yeast. All of these treatments are equally effective after four weeks of use.

Anti-inflammatory shampoos include:

• Tar (Z-Tar®, Pentrax®, DHS tar®, Ionil T plus®, and T-Gel extra strength®)
• Selenium sulfide (Selsun® and Exelderm®)
• Zinc pyrithione (Head and Shoulders®, Zincon®, and DHS zinc®)

Anti-yeast shampoos include:

• An antifungal medication (Nizoral®, Stieprox®)

The shampoo may be used every day initially, then every other day as symptoms improve. These shampoos can be used for as long as needed. If one type of shampoo does not improve symptoms after four to six weeks, a different shampoo may be tried. If the conditions worsens, consult with a healthcare provider.

Tea tree oil (Melaleuca oil) from an Australian tree has been used as a "natural" remedy for dandruff. However, products containing tea tree oil have may cause allergic skin reactions, and tea tree oil may affect male and female hormone levels. As a result, tea tree oil is not usually recommended as a treatment for dandruff.

Topical steroids (glucocorticoids) — A glucocorticoid cream, lotion, or liquid may be recommended to treat itching caused by seborrheic dermatitis. This treatment is most effective when used in combination with an antiseborrheic shampoo, even for areas not on the scalp.

Topical glucocorticoids are available in a variety of strengths (potencies); the least potent are available without a prescription (eg, hydrocortisone 1 percent cream). More potent formulations require a prescription. Low potency glucocorticoids (steroids) creams or ointments are usually recommended first.

These treatments are available in creams, ointments, and lotions for the face and in alcohol-based liquids, foams, and aerosol sprays for the scalp. The product should be applied daily until the dermatitis improves, then can be gradually discontinued.

Topical antifungal drugs — The antifungal medication ketoconazole (Nizoral®) is a prescription treatment that is available as a cream, foam, and gel. It is usually applied twice daily for several weeks. In cases of severe seborrheic dermatitis, treatment may include both topical glucocorticoids and topical or oral antifungal drugs.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed every four months on our Web site (www.uptodate.com/patients).

Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information

Patient information: Atopic dermatitis (eczema)
Patient information: Contact dermatitis (including latex dermatitis)
Patient information: Parkinson disease symptoms and diagnosis

Professional level information

Approach to the patient with a scalp eruption
Blepharitis
Overview of dermatitis

The following organizations also provide reliable health information.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/ency/article/000963.htm)

• American Academy of Dermatology

      (www.aad.org/public/publications/pamphlets/common_seb_dermatitis.html)

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