There are a few types of phototherapy for psoriasis.
- Narrow-band UVB - this is the most commonly used phototherapy to treat psoriasis. The wavelength of NBUVB is in the 311-313nm spectrum. Treatment is administered usually 2 to 3 times a week. There are machines that deliver treatment to the whole body and some machines that deliver treatment to target areas only.
- PUVA - this involves taking an oral drug, psoralen combined with UVA light. PUVA has more side effects compared with NBUVB as it can cause nausea, persistent photosensitivity during the day of treatment and has an increased risk of skin cancer.
- Excimer laser/light - this is used to treat localised areas of psoriasis.
- Bath PUVA - the body is soaked in a solution of psoralen followed by UVA light.
Before starting on phototherapy, your doctor will assess your suitability for the treatment and if there are any contra-indications to the treatment. You can ask your doctor more about the pro and cons of the different phototherapy treatment options.