PUVA is a psoralen + UVA treatment for eczema, psoriasis, graft-versus-host disease, vitiligo, mycosis fungoides, large-plaque parapsoriasis and cutaneous T-cell lymphoma. 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. PUVA can be effective for psoriasis even when UVB fails.
PUVA is a two-part therapy, consisting of exposure to psoralen followed by exposure to UVA light. UVA light activates psoralen, triggering its anti-psoriasis effects. Psoralens occur naturally in some plants and from as early as 1400 BC, people have used a combination of psoralen-containing plant extracts and sunlight to treat skin diseases. Modern PUVA therapy for psoriasis was developed in the 1970’s. There are many different psoralens, but the one used most often in PUVA therapy is methoxsalen, also known as 8-methoxypsoralen.
PUVA is good for those for those whose psoriasis is either severe or not responding adequately to more conventional forms of treatment. For example, psoriasis with very thick and scaly plaques on trunk and limbs. In approximately 90% PUVA is effective in clearing psoriasis, and can often control it as long as treatments are continued.
How PUVA Treatment is taken
Patients can take psoralen orally, 1-3 hours prior to UV light treatment (systemic PUVA) and alternatively they can soak for 15 minutes in a bath containing a dilute psoralen solution (bath PUVA). The patient is then exposed to UVA-emitting lamps. Treatments take place two or three times a week in a dermatologist’s office or clinic. After psoriasis clears, patients may switch to a maintenance regimen of less frequent treatments, because PUVA is sometimes used in conjunction with methotrextate, acitretin, or UVB.
Advantage of PUVA
The main advantage of PUVA is that they can be aimed directly at psoriasis plaques, sparing healthy skin from UV radiation damage Psoralens increase the skin's sensitivity to UV light, including sunlight. They are used to improve the effectiveness of UV light therapy for psoriasis. PUVA is used to treat psoriasis that has not responded to creams, ointments, or tar products used with UV exposure. It allows patients to restore a high quality of life.
Side Effects of PUVA
- An overdose of PUVA results in a sunburn-like reaction called phototoxic erythema. It is more likely in fair skinned patients who sunburn easily.
- Temporary mild pricking or itching of the skin is common after PUVA treatment.
- PUVA usually leads to tanning which lasts several months.
- For the PUVA treatment patient must be not younger than 18 years old and not older than 55 years old, because the UV light therapy may cause cataracts.
- There is a small risk of birth defects and it affected pregnant women, because of possible effects on a fetus.
- Patients who have years of PUVA therapy may develop other side effects. The most common is premature aging of the skin caused by exposure to the UVA light.