Psoriasis - Phototherapy

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Special Warning on PUVA and Skin Cancers. It has been known for some time that PUVA can change DNA and cause genetic mutations. PUVA is known to increase the risk for squamous cell skin cancer and slightly increase the risk for basal cell skin cancer, both of which are nearly always curable. One study also reported an increased risk of melanoma. The risk for skin cancers is higher in people who have:

• A family or personal history of skin cancer
• Light skin and fair or red hair
• Received radiation or x-ray treatments or taken immune suppressing drugs
• Received more than 200 PUVA treatments

Discussions are under way about discontinuing PUVA treatment of psoriasis. The following are pro and con arguments about the procedure:

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• Opponents of PUVA argue that studies suggest a long-term risk for melanoma, starting about 15 years after treatment, particularly in people who receive more than 250 treatments.
• Supporters of PUVA argue that it is not yet known whether the people who developed melanoma experienced sunburn during the procedures, or if they already had risk factors for skin cancers. If so, properly given treatments could still be considered safe for patients without risk factors. They also argue that PUVA is still the most effective treatment for severe psoriasis, and the alternatives are usually very powerful and relatively new drugs that may have even more serious side effects. Furthermore, adding retinoids may protect against skin cancers while increasing the treatment's effectiveness.

Protective Measures with PUVA Therapy

Side effects of UVA radiation can be severe. Protective measures are needed during, before, and after treatment. Patients should avoid prolonged exposure to the sun for 24 hours before the oral treatment starts.

Protective Measures During Treatment:

• Patients should wear specially designed goggles to protect the eyes from UVA radiation.
• Sensitive areas, such as the genitals, abdominal skin, and breasts should be covered until the exposed areas tan, which usually occurs after about a third of the treatment period. Because PUVA is associated with a high risk for genital skin cancers, male genitals must be covered throughout the process.