Psoriasis PUVA Treatment Can Increase Melanoma Risk

Sun-Damaged Skin Slideshow

Medical Editor: Melissa Conrad Stöppler, MD

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 and cyclosporine).

PUVA (psoralen and ultraviolet A radiation) treatment has been used for over two 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.

A report in the New England Journal of Medicine (1997;336:1041-5) described the study of 1,380 patients with psoriasis treated with PUVA in 1975/6. Dr. Robert Stern and colleagues 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. A follow-up study by the same authors in 2001 published in the Journal of the American Academy of Dermatology in 2001 (2001 May;44(5):755-61) described additional melanomas in the original patient cohort that arose after the 1997 findings, further confirming this risk and indicating 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 cancers of the skin. 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.

Because of the potential cancer risks, doctors recommend that patients who receive long-term PUVA treatment should be carefully monitored throughout their lives. These patients should also report to their health-care practitioners any peculiar skin abnormalities, including abnormally pigmented areas and skin that is changing color or size, itching, or painful.

For more information, please visit the Melanoma Center and Skin Cancer Center.