Topical treatments for psoriasis are medications that are applied directly to the skin on the affected area. This is usually considered to be the first-line choice of treatment for psoriasis due to the lower risk of systemic side effects.

Topical Corticosteroids

Corticosteroids are the most common treatment for psoriasis, used for their anti-inflammatory action that helps to reduce the redness and swelling associated with psoriatic lesions. There are various formulations available, including creams, ointments, shampoos, gels, sprays, solutions, lotions and foams.

There are various strengths of corticosteroid treatments available, from very strong (Class 1) to very weak (Class 7). As a general rule, stronger corticosteroid creams are more effective in the treatment of psoriasis but are also associated with higher risk of side effects.

Side effects of topical corticosteroids may include skin atrophy and sensitivity. Additionally, the medication can be absorbed systemically, particularly in high doses or when the treatment is covered, causing adverse effects to other areas of the body.

For moderate to severe psoriasis, topical treatment with corticosteroid cream alone is not typically sufficient and is commonly used in combination with other treatments.

Prescription Topical Treatments

There are also several other topical treatments for psoriasis available with a prescription. These include:

• Anthralin: A cream that reduces rapid skin cells growth associated with plaque psoriasis. Less commonly used due to brown staining when it comes into contact with healthy skin.
• Vitamin D Derivatives: A synthetic form of vitamin D that can be absorbed by the skin to slow cell growth and flatten lesions. (e.g. Dovonex, Taclonex, Vectical)
• Vitamin A Derivatives: A synthetic form of vitamin A and topical retinoid that may help to slow skin cell growth. (e.g. Tazorac)

Additionally, non-steroidal anti-inflammatory drugs (NSAIDS) is often prescribed for its action to reduce redness and swelling. Other agents include topical calcineurin inhibitors such as Protopic (tacrolimus) and Elidel (pimecrolimus).

Over-The-Counter (OTC) Topical Treatments

There are several over-the-counter topical treatments that may be used in the treatment of psoriasis, with varying degrees of success. These include:

• Salicylic Acid
• Tar
• Aloe vera
• Jojoba
• Zinc pyrithione
• Capsaicin
• Moisturizers and bath solutions

Of these, salicylic acid and tar are the most effective. Salacylic acid is a keratolytic agent that promotes peeling or shedding of the external of the skin, which is useful in the softening and removal of scales associated with plaque psoriasis. Tar is a natural therapy that helps to slow skin cell growth, restore skin appearance and reduce itching.

Topical Treatment Application

Most topical treatments for psoriasis should be applied to the affected area of the skin in a thin layer. Where possible, contact with unaffected areas should be avoided, and hands should be washed after application to reduce the risk of unnecessary irritation. Topical psoriatic treatments should never be applied to sensitive areas of the skin, such as the eyes, mouth, genitals and other areas.

In general, topical treatments need to be applied regularly for effective results. For precise advice for each treatment it is best to consult the individual medication information, but most formulations require dosing several times each day.

References

• https://www.psoriasis.org/document.doc?id=164
• https://www.psoriasis-association.org.uk/pages/view/about-psoriasis/treatments/first-line-treatments
• http://www.medscape.org/viewarticle/588415
• http://www.ncbi.nlm.nih.gov/pubmed/23543539