Proper use of topical psoriasis treatments


Corticosteroids are most effective when applied overnight and covered with airtight dressings. These dressings are changed in the morning, and they help the medication sink into the skin. Apply a thin layer of corticosteroid cream or ointment to the affected areas as directed by your doctor. Many people overuse these products, but using more than required won't make the medication work better or faster – it just wastes the medication. Ask your pharmacist or doctor how much to use. Wash your hands after applying corticosteroids. To avoid unwanted side effects, apply only a thin layer; do not use the medication more often or longer than your doctor recommends.

Calcineurin inhibitors

Calcineurin inhibitors (e.g., tacrolimus, pimecrolimus) are generally well-tolerated. They are not as effective as corticosteroids, but may help to avoid the complications of corticosteroids when applied to face or skin folds. Protect your skin with a sunscreen of at least SPF 15 when spending time outdoors, since these products can make your skin more sensitive to the sun.


At the start of treatment, calcipotriol is usually applied to the affected areas twice daily, then when the treatment has started to work well, it should be applied once daily. When applying it to the scalp, apply after washing your hair rather than before so that the medication is not washed away. Calcipotriol-betamethasone is applied once daily to the affected areas. Like most creams and ointments, you need to wash your hands after you apply calcipotriol or calcipotriol-betamethasone to remove any traces of medication so that you avoid transfer to the eye or a mucous membrane such as the mouth.*

Coal tar

Apply coal tar products to the affected area once daily. Be sure to apply it in the direction of hair growth and leave it on for at least 2 hours (or overnight). Since some coal tar products have a strong odour, you may wish to apply it at bedtime so that you do not need to "wear" it during the day. If you are using coal tar shampoo, apply it after wetting your hair, leave it on for 5 to 10 minutes, then rinse thoroughly.

Applying coal tar to broken skin or delicate areas such as the eyes or the inside of the nose or mouth may cause burning, stinging and irritation. Wash your hands after applying coal tar to avoid transfer to these areas or to clothing, since it will leave a stain. Protect your skin with a sunscreen of at least SPF 15 if you go outside, since coal tar can make your skin more sensitive to the sun.


Apply a thin layer of anthralin once daily to the affected areas and rub it in gently but thoroughly. Your doctor may recommend that you apply it at bedtime and remove it in the morning, or that you apply it and then wash it off after half an hour. You may be instructed to use an airtight dressing over top of the anthralin. Do not do this unless your doctor recommends it. To avoid irritation, avoid applying dithranol to your eyes, genitals, face, skin folds, or broken skin. As anthralin can stain skin, clothing, and surfaces, wash your hands well after applying it. To avoid staining your fingers, you may want to wear plastic gloves while applying anthralin.

Salicylic acid

Apply salicylic acid to affected areas as directed by your doctor. Many different salicylic acid products are available, so talk to your doctor or pharmacist to make sure you understand the instructions for your particular product. Do not apply it to broken skin, your eyes, inside your mouth, or inside your nose, as this may cause irritation. It's also important to wash all medications off your hands after applying salicylic acid.


Apply a thin layer of tazarotene to the affected areas once daily before bedtime. Wash your hands after applying. Since tazarotene can make your skin more sensitive to the sun, apply sunscreen with at least SPF 15 before going outside.

*Please note: These are general instructions based on how the medications are usually applied. If your doctor recommends using the medication in a different way than the instructions listed here, follow your doctor's recommendations.

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