How effective is phototherapy in treating psoriasis?

Very. Most psoriasis patients respond very well to phototherapy. If you get better with sunlight, it is very likely that phototherapy will lead to substantial improvement. Phototherapy is my favorite treatment when psoriasis can't be controlled with topical medicines.
Varies. In stable plaque psoriasis phototherapy can flatten psoriasis and put into remission for about 9 months. It will require a series of 20-30 treatments. Home narrow band uvb devices are available for home use and can be covered by insurance but will require documentation by a dermatologist.

Related Questions

Is phototherapy really good at controlling psoriasis?

Psoriasis Light Rx. Psoriasis is a autoimmune disorder that causes the build up of skin cells, with redness and scale. It was discovered along time ago that exposure to sun light helps psoriasis. Other, man made light sources are also used, . There are several kinds, using uva, or uvb, or narrow band uvb. Chemicals, like coal tar, are sometimes used with the light. The light can damage the skin and cause cancers.
Yes. But not always. The psoriasis can respond well to the light or phototherapy. We see this naturally because psoriasis does better in the summer when we have more sunshine. Unfortunately it does not always eliminate the psoriasis and then additional therapy may be necessary.