Psoriasis

What is psoriasis?

Psoriasis is a chronic relapsing inflammatory skin disease which affects about 2% of the population. The exact cause of psoriasis is unknown. It is due to a combination of genetic and environmental factors. There may be a positive family history. Some environmental factors which can worsen or trigger psoriasis include infections, stress, heat, sweating and certain drugs (e.g. propranolol).

Psoriasis typically appears as thick, scaly red patches on the scalp, hairline, ears, elbows, knees and lower back. Some patients may also have joint pain and deformed nails.

What is the treatment for psoriasis?

Although psoriasis may be difficult to cure, it can be effectively controlled in many people. The choice of treatment will depend on the severity of psoriasis, any medical conditions present and the patient’s preference.

The different types of treatment include topical medication, phototherapy, oral immunosuppressants and biologic injections.

Topical medication are often prescribed for localised areas of psoriasis. These include topical steroid, coal tar preparations, calcipotriol, immunomodulators and moisturisers.

Phototherapy is a type of ultraviolet light therapy using a laser (e.g. excimer laser) or special lamps (UVB or UVA). This is suitable for extensive psoriasis but will require multiple sessions over a period of several months.

Oral immunosuppressants have been used successfully in more extensive psoriasis. These include methotrexate and cyclosporin. They are prescribed for several months and blood test monitoring is required.

Biologics e.g. Cosentyx® (secukinumab), Stelara® (ustekinumab), Skyrizi® (risankizumab-rzaa) are new injectable medication for extensive psoriasis that has not responded to conventional treatments. Patients will require several injections a year and pre treatment tests are required.