Psoriasis | Types, Diagnosis, Complications & Treatment

2) Phototherapy

It is a well-known method of treatment of psoriasis that mainly involves scheduled skin exposure to ultraviolet rays. Ultraviolet rays are emitted naturally from the sun, yet dermatologists don’t usually recommend over-exposure to direct sunlight to avoid sunburns. Phototherapy which is also called light therapy is believed to reduce the size of the psoriatic patches and decrease the rate of growth of the skin cells. Ultraviolet radiations have three primary types; A, B, and C. The ultraviolet rays that are used in the treatment of psoriasis are UVA and UVB.

Patients could obtain UVB from special lamps or excimer lasers. The dermatologist will choose whether the psoriatic patient needs a broad-band or narrow-band UVB exposure according to the severity of psoriasis and the tolerability of the patient. UVA is not effective in the treatment of psoriasis unless a light-sensitizing agent is applied/taken orally before it in an approach called PUVA (psoralen + UVA). Phototherapy is less recommended in severe psoriasis occupying wide skin areas due to the higher risk of radiation side effects.