Phototherapy is a treatment for severe psoriasis. You may come to Great Ormond Street Hospital (GOSH) for one of two main types of phototherapy: UVB and PUVA.
UVB is a type of light that is found in normal sunlight. It is the simplest form of phototherapy as you do not have to take medication at the same time. Your doctor is unlikely to suggest this treatment unless you have tried special creams for psoriasis first (such as corticosteroids and tar applications). UVB treatment is not suitable for treating psoriasis in hair or for people who cannot come for treatment several times a week
You will usually have to visit the hospital three times a week for treatment and this will continue for four to six weeks. There are various machines for UVB treatments but they all involve fluorescent bulbs (a bit like the ones used on sunbeds). UVB is the part of sunlight that makes you burn. You will be given protective eyewear to wear during the treatment and will have to cover up areas that are not affected by the psoriasis. Sun block can also be used to protect skin that is not affected.
Each treatment will take only a few minutes. You will start with shorter treatments and gradually build them up.
Does it hurt?
UVB treatment might cause your skin to burn a little (like sunburn). If you experience more than a little bit of redness or tanning you should tell your dermatologist about this. The actual treatment should be painless.
Will a sun bed help?
No. The light produced by sunbeds is not suitable for treating psoriasis.
What about skin cancer?
There may be slightly higher risk of skin cancer with the use of this treatment. But the risk is still thought to be low. The risk of skin cancer is thought to be lower than when using PUVA treatments.
Make sure that you tell your dermatologist if you are on any medications. Some medicines can make your skin burn more easily so it is really important that they know to expect this.
Last reviewed: November 2011