Seborrheic dermatitis is a common skin disorder that mainly affects the scalp, causing scaly, itchy, red skin and stubborn dandruff. For infants, seborrheic dermatitis of the scalp is known as cradle cap. In addition to the scalp, seborrheic dermatitis can also affect the face, upper chest, back and other oily areas of the body.
It's neither harmful nor contagious, but seborrheic dermatitis can be uncomfortable and unsightly. You may be able to treat seborrheic dermatitis yourself by recognizing its signs and symptoms and by using a combination of self-care steps and over-the-counter (nonprescription) medications.
Though the exact cause of seborrheic dermatitis isn't known, several contributing factors seem to play a role, including an abnormality of the oil glands and hair follicles. People with this disorder seem to have increased oil (sebum) production.
It's also thought that in some people, a yeast (fungus) called malassezia grows in the sebum along with bacteria. Antifungal treatments, such as ketoconazole (Nizoral), are often effective, supporting the idea that yeast is a contributing factor.
Outbreaks may be linked with production of certain hormones, physical stress, fatigue, travel, change of season — outbreaks are usually worse in the winter — or illness. Seborrheic dermatitis may also occur more frequently in people who have neurological conditions, such as Parkinson's disease.
Seborrheic dermatitis may also accompany acne rosacea, an inflammatory skin condition that causes redness of the face. However, the vast majority of people with seborrheic dermatitis have no other associated skin conditions.
When to seek medical advice :
See your doctor if :
- You're so uncomfortable that you're losing sleep or are distracted from your daily routines
- Your skin is painful
- You suspect your skin is infected
- You've tried self-care steps without success
Common signs and symptoms of seborrheic dermatitis include :
- Patchy scaling or thick crusts on the scalp
- Yellow or white scales that may attach to the hair shaft
- Red, greasy skin covered with flaky white or yellow scales
- Small, reddish-brown bumps
- Itching or soreness
- Skin flakes or dandruff
Seborrheic dermatitis predominately affects the scalp but can occur between folds of skin and on skin rich in oil glands. These include in and between your eyebrows, the sides of your nose and behind your ears, over your breastbone, your groin area, and sometimes your armpits. You may experience periods when your signs and symptoms improve alternating with times when they become worse.
In infants, seborrheic dermatitis of the scalp is known as cradle cap. The patches may be thick, yellow, crusty or greasy. In most cases, the condition isn't itchy for infants like it is for older children or adults.
Your doctor may diagnose seborrheic dermatitis after talking to you about your symptoms and examining your skin and scalp. Sometimes, a skin biopsy or other tests are necessary to confirm the diagnosis and to rule out other types of dermatitis.
Conditions that are similar to seborrheic dermatitis include :
- Atopic dermatitis. This form of dermatitis is a chronic condition that causes itchy, inflamed skin. Most often, it occurs in the folds of the elbows, backs of the knees or the front of the neck. It tends to flare periodically and then subside for a time, even up to several years.
- Psoriasis. A skin disorder characterized by dry, red, skin covered with silvery scales. Like seborrheic dermatitis, psoriasis can affect the scalp and cause flaky dandruff. Psoriasis patches can range from a few spots of dandruff-like scaling to major eruptions that cover large areas of the body.
- Ringworm of the scalp (tinea capitis). Ringworm of the scalp is a type of fungal infection that is most common in toddlers and school-age children. It causes red, itchy, bald-looking patches on the scalp.
There's no cure for seborrheic dermatitis, but treatments can control its signs and symptoms. Treatment depends on your skin type, the severity of your condition and where it appears on your body.
Seborrheic dermatitis of the scalp
Medicated shampoos are the first step in treating seborrheic dermatitis of the scalp. Choose an over-the-counter shampoo that contains one of the following ingredients :
- Pyrithione zinc
- Selenium sulfide
- Salicylic acid
Try using the shampoo daily until your symptoms are controlled, then cut back to two or three times a week. If one type of shampoo works for a time and then seems to lose its effectiveness, try alternating between two types of dandruff shampoos. Be sure to leave the shampoo on for at least five minutes — this allows the ingredients time to work.
If you've shampooed faithfully for several weeks and you're still experiencing an itchy, flaky scalp, talk to your doctor or dermatologist. You may need a prescription-strength shampoo or more aggressive treatment with a steroid lotion.
Nonscalp seborrheic dermatitis
Treatments for nonscalp seborrheic dermatitis aim to reduce inflammation and the buildup of scaling on the skin. Over-the-counter (nonprescription) antifungal or anti-itch creams, along with other self-care measures, may help control your symptoms.
If these measures don't help, your doctor may prescribe topical corticosteroids, antifungal medications or a combination of the two to treat stubborn patches. A common course of treatment includes a daily regimen of ketoconazole (Nizoral) and desonide (Desowen) applied to your skin. Prescription oral medication, such as terbinafine (Lamisil), may be an option if the condition affects a large portion of your body.
A class of medications called immunomodulators, such as tacrolimus (Protopic) and pimecrolimus (Elidel), affects the immune system. These medications have anti-inflammatory and mild antifungal properties and are effective in treating seborrheic dermatitis. Due to possible concerns about the effect of these medications on the immune system when used for prolonged periods of time, the Food and Drug Administration recommends that Elidel and Protopic be used only after other treatments have failed, or if someone can't tolerate other treatments.