The acronym, PUVA, stands for Psoralen + Ultra Violet rays type A. The source of ultraviolet radiation UV could be natural (the sun) or artificial. Psoralen is a prescription medication that is very photosensitizing, i.e. a normally harmless quantity of UV rays could cause severe reactions of sunburn type. The severity of the reaction would also be expected to be due to the medication dosage as well as the amount of UV rays administered. Psoralen is much more
phototoxic when applied to the skin than it is after oral administration.
Oral PUVA consists of administering UVA rays in special irradiation chambers an hour or two after ingesting the drug psoralen. PUVA treatments are given once every two or more days, two to three times a week. After taking psoralen, skin reactions,
such as sunburn, can occur when exposed to an otherwise harmless quantity of light. Thus, ingestion of such a photosensitizing medication requires protection of the skin and the eyes until it has been totally eliminated from the body. The time interval between the ingestion of the medication and exposure to UVA light is one to two hours, depending on the brand of psoralen taken. If you anticipate taking any other photosensitizing medications or even large amounts
of photosensitizing foods during PUVA treatments, tell your doctor in order to avoid any undesirable side effects. Examples of photosensitizing foods are limes, figs, parsley, parsnips, mustard, carrots and celery. Some examples of photosensitizing medications include antidepressants [Elavil,Tofranil], antihistamines [Periactin, Benadryl], antimicrobial [Tetracyclines, Bactrim, Septra], antipsychotic drugs [Largactil, Moditen, Mellaril], diuretics [Lasix, Hydrodiuril,
hypoglycemics [Diabinese, Mobenol], anti-inflammatory drugs [Naprosyn, Feldene, Clinoril] and others [Capoten, Tegretol, Quinidine sulfate]. All these medications are much less phototoxic than psoralen.
EYE PROTECTION: Eye protection is crucial when taking UVA treatment. We face ultraviolet rays when we are exposed to daylight or to artificial sources of ultraviolet rays such as in the PUVA chambers. This exposure to daylight could also happen even through a window because window glass does not stop the penetration of ultraviolet rays. Eye protection is not required after sunset nor during exposure
to fluorescent or incandescent lamps. Eye protection should start immediately following the ingestion of the psoralen medication and continue for 6 to 8 hours until all traces of the medication are totally eliminated from the eyes. Eyes must be protected by UV-blocking wraparound Glasses. Sunglasses available on the market do not all block out ultraviolet rays and , even if they do, they do not offer lateral protection to the eyes. Some dermatologists allow
their patients to wear UV opaque contact lenses. As these lenses do not totally block UV rays, it is advisable to wear UV opaque sunglasses, particularly when outdoors. Furthermore, a pair of goggles, totally opaque to UV rays, should be worn during the treatment. To avoid contracting and transmitting infections, please have you own pair of goggles. Fortunately, patients undergoing PUVA treatments for the last 20 years failed to show an increased incidence of
cataracts compared to the general population as was expected to happen from the animal models. However, this does not mean that we should neglect eye protection.
PROTECTION OF THE SKIN: Sun exposure must be avoided on the day of the treatment. If you have to go into the sun, use sunscreens and wear appropriate clothing. Sunbathing should be avoided 24 hours before and 48 hours after the treatments. Avoid perfumes and perfumed products and use nothing but the products recommended by your dermatologist. Because the face and male genital organs are the most
prevalent sites for the development of skin cancer, we recommend you cover these areas during therapy sessions.
SIDE EFFECTS: Stomachache, one of the short term side effects that may occur, can be alleviated by taking psoralen with a glass of milk or food. It would also be helpful to take half the dosage one half hour before the time the medication is supposed to be taken and the other half on time. If still uncomfortable with oral psoralen, ask your doctor to take psoralen suppositories instead which
are available at certain pharmacies. Itching and dryness could be easily improved by emollients such as vaseline, glaxal base and moisturel.
Should any swelling and/or redness develop, you must inform your doctor immediately. Premature aging of the skin, elevated risk of non melanoma skin cancers (Basal cell epithelioma and Squamous cell epithelioma) and even, according to one study, melanoma skin cancers are possible if PUVA therapy is continued for extended periods of time. It is rather reassuring to find that after more than 20 years, the incidence of cataract in
humans has not been increased as predicted on the animal studies. That does not mean of course that eye protection should be neglected.
In spite of all these side effects PUVA remains the systemic treatment of choice compared to the other systemic agents used to control severe psoriasis. 95% of psoriasis cases clear within 30 treatment sessions.
Some diseases that respond to oral PUVA therapy: Psoriasis vulgaris, Polymorphous light eruption, Palmoplantar pustulosis, Pityriasis lichenoides, Mycosis Fungoides (early, stages IA, IB), Solar urticaria.
Some diseases that could respond to oral PUVA therapy: Vitiligo, Lichen Planus, generalized Alopecia Areata, Atopic eczema, Pityriasis rubra pilaris, generalized Granuloma annulare, Dyshidrotic czema, Hydroa vacciniforme, Transient Acantholytic Dermatoses, Lymphomatoid Papulsis, Urticaria Pigmentosa, Erythropeitic protoporphyria.