What is seborrheic dermatitis?
Considered a chronic form of eczema, seborrheic dermatitis appears on the body where there are a lot of oil-producing (sebaceous) glands like the upper back, nose and scalp. The exact cause of seborrheic dermatitis is unknown, although genes and hormones play a role. Microorganisms that live on the skin naturally can also contribute to seborrheic dermatitis.
Seborrheic dermatitis on the chest that shows round, red areas and slight scaling
Common triggers for seborrheic dermatitis include:
- Hormonal changes or illness
- Harsh detergents, solvents, chemicals and soaps
- Cold, dry weather
- Medications such as psoralen, interferon and lithium
In general, seborrheic dermatitis is slightly more common in men than in women. Patients with certain diseases that affect the immune system (such as HIV/AIDS and psoriasis) and the nervous system, such as Parkinson’s disease, are also at increased risk of developing seborrheic dermatitis. It can also affect people who have epilepsy, alcoholism, acne, rosacea and mental health issues such as depression and eating disorders.
Seborrheic dermatitis is not contagious.
What does seborrheic dermatitis look like?
Seborrheic dermatitis often appears on the scalp, where symptoms may range from dry flakes (dandruff) to yellow, greasy scales with reddened skin. Patients can also develop seborrheic dermatitis on other oily areas of their body, such as the face, upper chest and back.
Seborrheic dermatitis appears in oily skin areas like the side of the nose and causes redness and yellow scale
Common symptoms of seborrheic dermatitis include:
- Greasy, swollen skin
- White or yellowish crusty flakes
- Itch and burning
- Pink-colored patches, most prominent in people with dark skin
What causes seborrheic dermatitis?
The exact cause of seborrheic dermatitis is unknown, although genes and hormones play a role. Microorganisms such as yeast, that live on the skin naturally can also contribute to seborrheic dermatitis. Unlike many other forms of eczema, seborrheic dermatitis is not the result of an allergy.
People of any age can develop seborrheic dermatitis including infants (known as “cradle cap”). It is slightly more common in men than women.
People with certain diseases that affect the immune system, such as HIV or AIDS, and the nervous system, such as Parkinson’s disease, are believed to be at an increased risk of developing seborrheic dermatitis.
How is seborrheic dermatitis diagnosed?
Seborrheic dermatitis can often look like – or even appear with – other skin conditions such as atopic dermatitis and psoriasis.
There is no test for diagnosing seborrheic dermatitis. Your doctor will ask about your medical history and also perform a physical examination of your skin. Sometimes, the doctor with scrape a bit of skin, mix it with a chemical and look at it under a microscope to determine if there is a fungal infection. Similarly, a skin biopsy (a procedure in which a small sample of skin is taken) may be required to rule out the other conditions that look like seborrheic dermatitis.
If you are experiencing symptoms, make an appointment with your doctor to get the correct diagnosis and treatment.
Seborrheic dermatitis treatment
Treatment for seborrheic dermatitis focuses on loosening scale, reducing inflammation and swelling, and curbing itch.
In mild cases, a topical antifungal cream or medicated shampoo (such as ketoconazole, selenium sulfide, coal tar, and zinc pyrithione) may be enough to control symptoms.
Guidelines for treating seborrheic dermatitis include:
- For the scalp: Alternate between using your regular shampoo and a medicated dandruff shampoo. If you are African American, wash with the medicated shampoo once weekly. Taper off as your symptoms improve.
- For the body: Wash daily with a gently cleanser that has 2% zinc pyrithione, followed by a moisturizer. To further soften scale, use a cream containing salicylic acid and sulfur or coal tar.
In more severe cases, you may receive a prescription for a mild corticosteroid medication to calm the inflammation as well. Use topical corticosteroids only as directed—that is, when the seborrheic dermatitis is actively flaring.
In cases where corticosteroids are not appropriate, or when they have been used for a prolonged period, a non-corticosteroid topical medication such as tacrolimus (Protopic) or pimecrolimus (Elidel) may be prescribed. These medications are called topical calcineurin inhibitors (TCIs) and are approved for use by adults and children two years of age or older. Oral antifungal agents may be used in very severe cases.