Oral Psoralen Phototherapy with Ultraviolet A Light
What is PUVA therapy?
PUVA therapy (Psoralen + Ultraviolet A Light) is an approach used to treat certain chronic skin diseases such as psoriasis, vitiligo, and mycosis fungoides. Therapy consists of the combination of an oral medication called Psoralen (Oxsoralen Ultra) and subsequent exposure to long wave ultraviolet A light. The combination slows down the rate of cell growth in areas affected by the disease. PUVA treatments are given 2-3 times per week. In most people, about 25 treatments are needed to see improvement. The duration of remissions and need for continued therapy varies greatly among patients.
Almost immediately after taking Psoralen, the skin and eyes become increasingly sensitive to UVA light. The skin’s peak sensitivity to UVA occurs between 1-2 hours after taking the capsules.
What are sources of UVA?
- The sun is a strong source of UVA light. This wavelength of light is not screened out by clouds, window glass, or sunscreens. Care must be taken to avoid all sun exposure for 24 hours after taking Psoralen.
- The light cabinet provided measured and controlled source of UVA light. The light cabinet is like a closet lined with special light bulbs that emit UVA light. Treatment is the cabinet is termed phototherapy. We also offer a foot and hand light box for people with palmoplantar pustulosis.
How is PUVA administered?
Your physician will determine the correct amount of Psoralen to be taken based on your weight. The medication should be taken 1 hour before your scheduled appointment. Occasionally the Psoralen causes nausea. To help prevent this, take the capsules with food. You may also split your dose, taking half the capsules at one time and the other half 30 minutes later, i.e. at one hour and at 1.5 hours before UVA treatment. Since the amount and rate of absorption of Psoralen varies with the amount of food in your stomach, be consistent in how you take Psoralen. It should be taken with the same amount of food each time. You are required to wear specially designed protective glasses for your treatments. They can be purchased in the office.
Let the nurse know if:
- Less than 1 hour has passed since taking Psoralen.
- More than 2.5 hours have passed since taking Psoralen.
- You have not taken the prescribed dosage of Psoralen.
You will receive the UVA light by standing unclothed in the light cabinet or sitting at the hand and foot machine with your feet and hands exposed. Males must not expose their genitalia during PUVA treatments. An athletic supporter is adequate to shield male genitals during treatment. The amount of light exposure begins with just a few minutes and increases each treatment. Treatments usually last from 1-20 minutes.
What are the side effects of PUVA?
- People using PUVA therapy are at greater risk for developing skin cancers. The risk of such tumors also increases with repeated and prolonged exposure to the sun. Avoid all sun exposure for 24 hours after taking Psoralen. If sunlight exposure is unavoidable, wear protective clothing, broad-spectrum sunscreen, and avoid the mid-day sun. The male genitalia are especially sensitive to the effects of PUVA light. All people receiving PUVA therapy should have complete skin examinations at least yearly and should perform monthly self-exams.
- Psoralen makes the eyes more sensitive to light’s damaging effects and hence, more susceptible to cataract formation. Protective eyeglasses(available for purchase) must be worn for 24 hours after taking Psoralen. You should wear the glasses during the daylight hours unless you are in a building with no windows in your area. Do not substitute any other glasses for those provided. Complete ophthalmic exams should be obtained before treatments begin, 6 months after treatment begins, and yearly while on therapy.
- Premature aging of the skin may be a potential long-term risk of PUVA treatment, as seen in prolonged sun exposure. Some people will develop freckles in areas treated with PUVA light. Redness and dryness of the skin is to be expected during the first weeks of therapy. Most people’s skin will tan. The tanning may be uneven at first with skin color being lighter in areas where the disease has been prevalent.