Psoriasis PUVA Treatment Can Increase Melanoma Risk

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Psoriasis is a chronic disorder of the skin characterized by reddish, scaly patches of inflammation, most commonly affecting the elbows, knees, scalp, and/or groin. Psoriasis can be mild or severe. When it is severe, it can adversely affect functions of daily living, including work and social activities.

Psoriasis has been reported to affect approximately 2% of the world's population.

The treatment of psoriasis depends on its severity and location. Treatments range from local (cortisone cream application, emollients, coal tar, anthralin preparations, and sun exposure) to systemic (internal medications, including methotrexate [Rheumatrex, Trexall] and cyclosporine).

PUVA (psoralen and ultraviolet A radiation) treatment has been used for decades to treat severe psoriasis. In this "combination" therapy, the psoralen, taken internally, acts as a skin sensitizer. The "sensitized" skin affected by psoriasis can then be treated by ultraviolet A radiation.

Researchers at Harvard Medical School found that about 15 years after the first PUVA treatment, the risk of malignant melanoma increased more than fivefold, with the greatest risk observed in patients who received 250 treatments or more. Moreover, additional longer-term research confirmed this risk and indicated that the risk of melanoma increases with time in this patient population.

PUVA treatment is known to be highly effective for psoriasis and other skin conditions, allowing patients to resume normal life activities. PUVA has previously been shown to increase the risk for skin cancer. Melanoma, a fatal form of skin cancer if not treated, has now been added to the list of skin cancers that occur more frequently after a number of PUVA treatments.