In the majority of patients, sun radiation proves favourable and visibly reduces the skin manifestations. Interestingly, phototherapy can also be used in patients in whom exposure to sun light may make the symptoms worse. This is because light lamps emit a safe and beneficial range of ultraviolet light.
Phototherapy needs to be applied consistently and regularly, under permanent medical control. Like any other medical therapy, phototherapy is associated with a risk of side effects, including phototoxicity, accelerated skin ageing, acute inflammation of cornea and conjunctiva, and skin cancer.
Phototherapy in psoriasis is delivered through various methods based on UVA and UVB light.