context: At least half of people with psoriasis have it on their scalp. The skin cells on your scalp grow too quickly and make powdery or thick scales called plaques. The areas around them can be red and itchy. Scalp psoriasis can cause everything from mild scaling to crusting on the entire scalp -- sometimes extending onto the forehead, around the nose, in the beard area, or behind or inside the ears. If you have mild scaling, it may get better on its own. Sometimes, though, you'll need treatment. It can take a couple of months or longer to get more severe dandruff under control. Once you do, you may be able to keep it from flaring with special shampoos or moisturizers. There's no cure for psoriasis, but you can take a number of steps to manage it. Your treatment will depend on: How severe it is How it has responded to treatment before Whether you have psoriasis elsewhere on your body How much hair you have The most common treatments for mild cases are medications that you put directly on your scalp. If you have a more severe case or have psoriasis elsewhere on your body, you may need a medication that treats your whole body. You can take these medications by mouth or injection. If your psoriasis doesn't respond well after repeated use of one medication, your doctor may replace or combine it with another type of treatment. One of the first steps is to soften and remove scales. This makes it easier for medications to do their job. Apply over-the-counter ( OTC) products to your scalp to help soften scales and make them easier to peel off. Look for products with the active ingredients salicylic acid, lactic acid, urea, zinc pyrithione, or selenium sulfide. Gently loosen the scales with a brush or fine-toothed comb. Shampoo your scalp to remove the scales, using a salicylic acid shampoo or soap. Apply thick creams to your scalp while it's still damp to hold in the moisture. To apply medication: Put petroleum jelly on cotton balls, and put them into your ears to keep the medications for your scalp out of your ears. Do not use cotton balls if you are also treating psoriasis in your ear canals. Use medications sparingly. They may cause skin irritation and can weaken hair shafts, causing temporary hair loss. With an oil or lotion, part your hair and drip the medication onto your scalp. With a cream or ointment, rub it right into your scalp. Covering your scalp with a shower cap for a short period of time may help some medications work better, but check with your doctor first. Your doctor may recommend these: Coal tar products are available OTC as shampoos, creams, gels, ointments, foams, and soaps. They can help slow skin growth and reduce inflammation, itching, and scaling. To apply a coal tar shampoo, massage it into the scalp and leave on 5 to 10 minutes before rinsing out. You can leave other tar products on overnight. Staining and odor are the main drawbacks. A non-medicated conditioner after shampooing can help against the odor of tar shampoo. Salicylic acid is a peeling agent available in OTC and prescription shampoos and soaps. It can soften scales, making them easier to remove. Medicated shampoos are available in coal tar and non-coal tar varieties. You can use these daily for scalp plaques, but follow the directions. Intralesional steroid injections can reduce inflammation. A doctor uses a small needle to inject medication into scalp plaques. You can have this procedure at the doctor's office. To ease itchiness: Use a conditioner after shampooing. Limit hot tools for hair styling. Use wet towels, cold packs, or cold water on itchy spots. Try OTC tar shampoos or ones with menthol or phenol creams. You can also check with your doctor about taking OTC antihistamine pills. Your doctor may prescribe steroids, lotions, solutions, sprays, or foams to treat moderate to severe scalp psoriasis. Some topical treatments are applied directly to the skin, then shampooed and rinsed out, including: Anthralin ( Psoriatec). Apply this cream once a day for 10 to 30 minutes. Calcipotriene ( Dovonex). This is a prescription form of vitamin D. Apply it at night and cover your scalp with a shower cap. Leave it on overnight. Don't get it in your eyes. Calcipotriene and betamethasone dipropionate ( Taclonex Scalp, Enstilar Foam). This is a combination of a type of vitamin D and a strong steroid in a suspension or ointment. You use it once a day. Don't get it in your eyes. Tazarotene ( Tazorac). This vitamin A treatment comes in a cream, foam, or gel form. If using it at night, put it on clean, dry skin, and let the medication dry before you go to sleep. Applying a moisturizer after the medication may help prevent drying. Follow your doctor's directions for all medications. Don't use stronger steroids for more than a 2-week cycle without your doctor giving you the OK. If you have moderate to severe psoriasis elsewhere on your body, one of these medications may help: Methotrexate slows an enzyme involved in the rapid growth of skin cells. Oral retinoids help control the growth of cells. Cyclosporine lowers the immune system function, and therefore helps to reduce the inflammation of psoriasis. Biologics target specific parts of the immune system that are overactive in psoriasis. Talk with your doctor about the potential side effects of these treatments. Ultraviolet ( UV) light is another treatment option. Hair can block the light from reaching your scalp, so if you have thick hair, it may help to part it in rows. Hand-held devices ( UV combs) can directly deliver light to your scalp. If your scalp psoriasis becomes infected, you may have crusting, redness, warmth, tenderness, and sometimes swelling of your lymph nodes. Your doctor may prescribe an antibiotic treatment for this problem.