Phototherapy is the use of ultraviolet (UV) light to slow the rapid
growth of new skin cells. This is helpful in treating
, which causes skin cells to grow too
rapidly. There are two types of
Ultraviolet B (UVB)
- Exposure times start at 30 to 60 seconds when therapy begins. You are exposed to the light until it causes the skin to turn slightly pink. When the skin no longer turns pink in the 24 hours after a treatment, the exposure time is increased.
- Treatments are given several times a
week until the psoriasis clears up.
- UVB light is used alone, with tar products (Goeckerman
treatment), or with anthralin applied to the skin (Ingram regimen).
One phototherapy option includes the use of narrow-band UVB light.
This exposes you to only the wavelengths of light that work for
treating psoriasis. Broadband UVB therapy uses a wider range of wavelengths.
A laser treatment for psoriasis (excimer laser) also uses UVB light. Excimer laser works well for psoriasis that has been hard to treat on the elbows and knees.1
Ultraviolet A (UVA)
- UVA penetrates deeper into the skin than UVB.
- Treatment with UVA typically takes 20 minutes for a
- UVA light used with psoralen drugs is called PUVA. With
PUVA, the treatment time is greatly reduced, from 20 minutes to about 2
Treatments with UVB and UVA
Phototherapy can be used alone or with medicines. UVB light
therapy is used alone to treat severe psoriasis. Typically, when medicines for
psoriasis are used with light therapy, you will use or take the medicine first.
You may apply it to your skin, take it by mouth, or use it as bath salts in
water. Then you will go into a booth and be exposed to the UV light. Using two
kinds of treatment is called combination therapy. Three common combination
which combines UVA exposure and a medicine (called a psoralen) that makes your
skin more sensitive to light.
- The Ingram regimen, which combines
products, and UVB phototherapy.
- The Goeckerman
treatment, a combination of
tar products and UVB phototherapy.
Your body is exposed to UV light from banks of light tubes that
give off either UVB or UVA light in a booth. Booths come in several
designs. Some look like phone booths and you can stand in them. Others look
like tanning beds and you can lie down during treatment. The booth will
record the total amount of light you are exposed to.