How Effective is Phototherapy?

narrow-band ultraviolet b uvb therapy

Phototherapy is effective in clearing up or reducing the symptoms of psoriasis. 
The use of narrow-band ultraviolet B (UVB) therapy is most common. Studies have shown that narrow-band UVB treatments are effective against a rarer form of psoriasis called acute guttate psoriasis.

Using phototherapy to treat psoriasis results in noticeable improvement or a complete reduction of symptoms in 50 to 90 percent of patients.

Is Phototherapy Safe for Everyone?

Phototherapy is a safe form of treatment but there may be more risks or side effects if you have certain medical conditions. Your dermatologist will let you know if light therapy is a good option for you. 

Phototherapy may not be recommended if:

  • You are pregnant or nursing.
  • You have some sort of sun allergy that causes you to break out in hives when exposed to the sun. This is a rare condition, but not a real allergy.
  • You have liver disease.
  • You have lupus.
  • You have a medical condition that makes you more likely to develop skin cancer such as Xeroderma Pigmentosum.
  • You have a melanoma or any other type of skin cancer.
  • You take medication that makes you more sensitive to UV light such as antibiotics, antifungals, and diuretics.

How Effective are the Different Types of Phototherapy?

Phototherapy is often an effective treatment for psoriasis. It is estimated that the
symptoms improve noticeably or go away completely for a while in at least 50 percent of those with the condition.

It is currently thought that PUVA using psoralen tablets is more effective than narrow band UVB phototherapy. But side effects are also more common, and the associated risk of skin cancer may be greater. So, it is a good idea to talk to your doctor and carefully weigh the pros and cons of PUVA therapy using psoralen tablets.

Narrowband UVB

Narrowband UVB has proven itself as a tried-and-true form of therapy used by
dermatologists in their practice. The effectiveness of narrowband UVB therapy for
psoriasis prompted the release of joint guidelines from the American Academy of
Dermatology and the National Psoriasis Foundation on the risks and benefits of this treatment. The guidelines are somewhat general, but for practitioners who are using phototherapy, it is helpful to have a ground rule in terms of the different light sources that they can use or recommend to patients and how to dose patients. 

In the guidelines, experts recommend narrowband UVB treatment two or three times a week. There is also a warning that a greater frequency results in minimal benefit and may only expose a patient to a higher total dose of UVB radiation that can lead to a greater risk for UV-induced erythema. They advised that a thin layer of emollient should be applied before treatment to increase effectiveness and reduce erythema.

Narrowband UVB lamps for home use can also be considered, according to the