Treating psoriasis ^1,2,3

Over-the-counter topical medications

These are treatments that are applied directly to the skin and include moisturisers and bath solutions. Keeping the skin well moisturised is important to lock in moisture and can help reduce itchiness and redness. Over-the-counter medications contain ingredients such as tar and salicylic acid which can all help to settle the inflammation and increased flakiness of the skin.

Prescription topical medications

These treatments are also applied directly to the skin, but have to be prescribed by a doctor. They include steroids which reduce the inflammation. Steroids vary in potency and must always be used according to your doctor’s instructions. Other treatments include anthralin, vitamin A (tazarotene) and vitamin D derivatives. There are also some tar and salicylic based medications that are available by prescription only.

Light therapy (Phototherapy)

Approximately 80% of people with psoriasis notice an improvement in their skin after spending time in the sun. Light therapy involves exposing the skin to one of the two types of the sun’s ultraviolet light under medical supervision. The treatments are given up to three times per week in a clinic, and may take up to 30 sessions before positive improvements are seen.

PUVA therapy

PUVA therapy combines ultraviolet A (UVA) light present in sunshine with a psoralen, a medication that sensitizes the skin to UVA and makes treatment more effective. The psoralen can be taken as a tablet or in a bath-soak prior to therapy. 

UVB therapy

Treatment with ultraviolet B (UVB) involves exposing the skin to an artificial UVB light source for a set period of time on a regular basis, under a doctor's supervision in a clinic.

Systemic treatments

Systemic treatments are prescription only medicines and are generally for patients with moderate-to-severe disease that are unresponsive to topical treatments and/or phototherapy. These drugs work throughout the entire body and as a result, use of these treatments can be associated with short- and long-term side effects. The degree of skin clearance achieved must be weighed against these side effects. The four most commonly prescribed treatments are methotrexate, ciclosporin, acitretin and hydroxycarbamide. Methotrexate, ciclosporin and hydroxycarbamide all work by suppressing the immune system, whereas acitretin is a Vitamin A derived treatment.

Biologics

A more recently developed type of systemic therapy is ‘biologic’ treatment.  Unlike other medicines which are made by combining chemicals, biologics are created from human or animal proteins. 

Biologics are designed to target specific molecules involved in immune reactions that are implicated in the development of psoriatic plaques.  Current biologic therapies target proteins involved in inflammation or their receptors.

References:

1. Gottlieb, A. Psoriasis: Emerging Therapeutic Therapies, Nature Reviews volume 4, January 2005
2. The Psoriasis Association. Treatments: http://www.psoriasis-association.org.uk/treatments.html Accessed February 2009
3. The National Psoriasis Foundation. http://www.psoriasis.org/home/learn03.php Accessed February 2009