Seborrheic dermatitis signs and symptoms may include:

• Flaking skin (dandruff) on your scalp, hair, eyebrows, beard or mustache
• Patches of greasy skin covered with flaky white or yellow scales or crust on the scalp, face, sides of the nose, eyebrows, ears, eyelids, chest, armpits, groin area or under the breasts
• Rash that may look darker or lighter in people with brown or Black skin and redder in those with white skin
• Ring-shaped (annular) rash, for a type called petaloid seborrheic dermatitis
• Itchiness (pruritus)

The signs and symptoms of seborrheic dermatitis tend to flare with stress, fatigue or a change of season.

When to see a doctor

See your health care provider if:

• You're so uncomfortable that you're losing sleep or are distracted from your daily routines.
• Your condition makes you feel embarrassed or anxious.
• You think your skin is infected.
• You've tried self-care steps, but your symptoms persist.

The exact cause of seborrheic dermatitis isn't clear. It may be due to the yeast Malassezia, excess oil in the skin or a problem in the immune system.

Risk factors for seborrheic dermatitis include:

• Stress
• Fatigue
• A change of season
• Nervous system conditions, such as Parkinson's disease
• Having a mental health condition, such as depression
• Immune system disorders, such as HIV infection
• Recovery from stressful medical conditions, such as a heart attack

To diagnose seborrheic dermatitis, your health care provider will likely talk with you about your symptoms and look at your skin. You may need to have a small piece of skin removed (biopsied) for study in a lab. This test helps rule out other conditions.

For adolescents and adults, the main treatments for seborrheic dermatitis are medicated shampoos, creams and lotions. If nonprescription products and self-care habits don't help, your health care provider might suggest that you try one or more of these treatments:

• Antifungal gels, creams, lotions, foams or shampoos alternated with another medication. Your health care provider might suggest you try a product with 2% ketoconazole or 1% ciclopirox (Loprox). Or you might rotate between two or more products. Ketoconzole can worsen the dryness of tightly coiled or chemically treated hair and increase the risk of breakage. To ease this effect, use it only once a week with a moisturizing conditioner.

  How often you shampoo or apply other antifungal products will depend on your hair-grooming practices and symptoms. Medicated shampoos can be used once a day or 2 to 3 times a week for several weeks. Let the product sit on your scalp for a few minutes — see package directions — so it has time to work. Then rinse. After your symptoms clear up, use a medicated shampoo just once a week or once every two weeks. This will help prevent a relapse.

• Creams, lotions, shampoos or ointments that control inflammation. Your health care provider might prescribe a prescription-strength corticosteroid you apply to the scalp or other affected area. These include hydrocortisone, fluocinolone (Capex, Synalar), clobetasol (Clobex, Temovate) and desonide (Desowen, Desonate). They are effective and easy to use. And use them only until symptoms clear up. If used for many weeks or months without a break, they can cause side effects. These include loss of skin color, thinning skin, and skin showing streaks or lines.

  Creams or ointments with a calcineurin inhibitor such as tacrolimus (Protopic) or pimecrolimus (Elidel) may be effective. Another benefit is that they have fewer side effects than corticosteroids do. But they are not first-choice treatments because the Food and Drug Administration has concerns about a possible association with cancer. In addition, tacrolimus and pimecrolimus cost more than mild corticosteroid medications.

• Antifungal medication you take as a pill. If your condition isn't improving with other treatments or is severe, your health care provider may prescribe an antifungal medication in pill form.

You may be able to control seborrheic dermatitis with lifestyle changes and home remedies. Many of these are sold in nonprescription forms. You may need to try different products or a combination of products before your condition improves.

The best approach for you depends on your skin type, hair-grooming practices and your symptoms. But even if your condition clears up, it's likely to come back at some point. Watch for the symptoms and resume treating the condition when it recurs. Or use nonprescription antidandruff products in your self-care routine to prevent flare-ups.

Wash your scalp regularly

If regular shampoo doesn't help with dandruff, try nonprescription dandruff shampoos. They are classified according to the active ingredient they contain:

• Pyrithione zinc (DermaZinc, Head & Shoulders, others), also sold as bar soap
• Selenium sulfide (Head & Shoulders, Selsun Blue, others)
• Ketoconazole 1% (Nizoral A-D)
• Tar (Denorex Extra Strength, DHS Tar, others)
• Salicylic acid (Denorex, DHS Sal, others)

How often you shampoo or apply other antifungal products will depend on your hair-grooming practices and symptoms. Medicated shampoos can be used once a day or 2 to 3 times a week for several weeks. After your symptoms clear up, use a medicated shampoo just once a week or once every two weeks. This will help prevent a relapse. Shampoo that contains tar or selenium sulfide can discolor light-colored hair.

Sometimes a shampoo that has helped loses its effectiveness over time. If that's the case, try alternating between two or more types. Be sure to leave your shampoo on for the full recommended time — this allows its ingredients to work. Then rinse. These shampoos may be rubbed gently on the face, ears and chest and rinsed off well.

Other home remedies

The following nonprescription treatments and self-care tips may help you control seborrheic dermatitis:

• Soften and remove scales from your hair. Apply mineral oil, peanut oil or olive oil to your scalp. Leave it in for 1 to 3 hours. Then comb or brush your hair and wash it.
• Wash your skin regularly. Use warm, not hot, water and a gentle soap or nonsoap cleanser. Rinse thoroughly. Pat dry and apply a moisturizer while your skin is still damp.
• Apply a medicated cream. First try a mild corticosteroid cream, foam, ointment or oil (Scalpicin Scalp Itch) on affected areas, keeping it away from the eyes. If that doesn't work, try the antifungal cream ketoconazole.
• Don't use styling products. Stop using hair sprays, gels and other styling products while you're treating the condition.
• Don't use skin and hair products that contain alcohol. These can cause the disease to flare up.
• If you have a beard or mustache, shampoo facial hair regularly. Seborrheic dermatitis can be worse under mustaches and beards. Shampoo with 1% ketoconazole daily until your symptoms improve. Then switch to shampooing once a week or once every two weeks. Or shaving might ease your symptoms.
• Gently clean your eyelids. If your eyelids are inflamed or scaly, wash them each night. Use a few drops of baby shampoo mixed with two capfuls of warm water. Wipe away scales with a cotton swab. Warm, damp cloths pressed to your eyelids also may help.
• Gently wash your baby's scalp. If your infant has mild cradle cap, wash the scalp with a mild baby shampoo once a day. Gently loosen the scales with a cloth or an infant hairbrush before rinsing out the shampoo. If scaling persists, first apply mineral oil or olive oil to the scalp for an hour or two. Cradle cap usually disappears in a few weeks or months.

Many alternative therapies, including those listed below, have helped some people manage their seborrheic dermatitis. But evidence for their effectiveness isn't proved. It's always a good idea to check with your health care provider before adding any alternative medicines to your self-care routine.

• Tea tree oil. A shampoo with 5% tea tree oil may be used on the affected area. Some studies suggest that tea tree oil can trigger an allergic reaction.
• Aloe. Apply aloe vera gel to the affected area. Aloe is an ingredient in many products, or you can use it directly from the leaf of an aloe plant.

If you're considering dietary supplements or other alternative therapies, talk with your health care provider about their pros and cons.

You'll probably first visit your primary care provider. Or you may see a doctor who specializes in the diagnosis and treatment of skin conditions (dermatologist).

Here's some information to help you get ready for your appointment.

What you can do

Before your appointment, list your answers to the following questions:

• What are your symptoms, and when did they start?
• Does anything seem to trigger your symptoms?
• What medications are you taking, including those you take by mouth as well as creams or ointments?
• What treatments have you tried so far? Has anything helped?

What to expect from your doctor

Your health care provider is likely to ask you a few questions. Being ready to answer them may free up time to go over any points you want to spend more time on. Your health care provider might ask:

• What are your symptoms, and when did you first notice them?
• Is this the first time you've had these symptoms, or have you had them before?
• How severe are your symptoms? Are they about the same all the time, getting worse, or sometimes better and sometimes worse?
• Do your symptoms affect your quality of life, including your ability to sleep?
• Have you tried any at-home treatments, such as creams, gels or shampoos?
• How often do you use these treatments?
• Does anything seem to help?
• Does anything seem to make your symptoms worse?
• What medications, vitamins or supplements are you taking?
• Have you been under stress lately or experienced major life changes?

What you can do in the meantime

A nonprescription antifungal cream or anti-itch cream can be helpful. If your scalp is affected, a nonprescription antifungal shampoo, foam or other product may ease your symptoms. Try not to scratch or pick at the affected area. This increases your risk of infection.