PUVA Therapy – What It Is and How It Works

If you’ve heard doctors mention PUVA therapy, you might wonder what the letters stand for and why it’s used. PUVA combines a drug called psoralen with exposure to UVA light. The drug makes your skin more sensitive to the light, so a lower dose of UVA can do the job. This simple chemistry helps slow down the rapid cell growth that causes plaques in psoriasis or repigment patches in vitiligo.

How PUVA Therapy Works

The process starts with taking psoralen—either as a pill you swallow or a cream you apply to the skin. After about an hour, you step into a special light booth that emits UVA rays. The session usually lasts 10‑15 minutes, but the exact time depends on your skin type and how your body reacts.

During exposure, the psoralen molecules sit inside the top layers of skin cells and absorb the UVA energy. This slows down DNA replication in those cells, which reduces the overgrowth that creates thick, scaly patches in psoriasis. For vitiligo, the same effect helps stimulate melanin production, gradually bringing back color to white spots.

Benefits, Risks, and What to Expect

Many patients see improvement after just a few weeks of twice‑weekly sessions. PUVA can clear up stubborn plaques that don’t respond to topical creams or steroids. It’s also one of the few options that actually helps repigment vitiligo patches.

But it’s not without downsides. The most common side effect is skin redness, similar to a mild sunburn. Some people get itching or dryness that clears up with moisturizers. Long‑term use can increase the risk of skin aging and, rarely, skin cancer, so doctors limit the total number of treatments.

Before you start, your dermatologist will check your medical history, especially for liver issues or eye problems, because psoralen travels through the bloodstream. You’ll also need to wear UV‑blocking glasses during the session to protect your eyes.

After each treatment, apply a fragrance‑free moisturizer and avoid direct sunlight for at least 24 hours. If you notice persistent burning or new moles, call your doctor right away.

Overall, PUVA therapy can be a powerful tool when other treatments fall short. It’s most effective when combined with a solid skin‑care routine and regular follow‑ups with your dermatologist. Talk to your provider about whether PUVA fits your situation, and you’ll have a clear picture of what the weeks ahead will look like.