PUVA Therapy (Photochemotherapy)

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Medical Author:

Gary W. Cole, MD, FAAD

Gary W. Cole, MD, FAAD

Dr. Cole is board certified in dermatology. He obtained his BA degree in bacteriology, his MA degree in microbiology, and his MD at the University of California, Los Angeles. He trained in dermatology at the University of Oregon, where he completed his residency.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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What is PUVA?

PUVA is an acronym. The P stands for psoralen, the U for ultra, the V for violet and the A for that portion of the solar spectrum between 290 and 320 nanometers in wavelength. Psoralens are chemicals found in certain plants that have the ability to absorb ultraviolet light in these wavelengths. Once the light energy is absorbed, these chemicals are energized to interact with DNA, ultimately inhibiting cell multiplication, which is their presumed mode of action.

Certain skin diseases are characterized by cells that are rapidly multiplying. Inhibiting this unrestrained multiplication can be useful in treating these diseases. So PUVA is a combination of an oral drug and subsequent ultraviolet light exposure. The treatment may affect certain blood cells and skin cells so that the skin disease clears.

What diseases does PUVA therapy treat?

One of the skin diseases for which PUVA is used and for which it was originally developed is psoriasis. The psoralen, 8-methoxy psoralen (8-MOP) (Oxsoralen), is used for the treatment of psoriasis along with exposures to ultraviolet light in the UVA spectrum. PUVA is also of benefit in treating vitiligo, mycosis fungoides (cutaneous T cell lymphoma), and graft versus host disease.

What are the different types of PUVA therapy?

The most common form of therapy combines psoralen 8-methoxypsoralen taken by mouth followed 45-60 minutes later by exposure of the skin to ultraviolet light. Less commonly the drug is applied topically (the medication is occasionally diluted in bathtub water in which the patient is immersed) and then after a few minutes the ultraviolet exposure occurs.