Skip to Content
Home > Wellness > Health Library > Psoralen and UVA Light Therapy (PUVA) for Psoriasis
Psoralen medicines are available as pills, lotions, or bath salts. A psoralen medicine is taken 1½ to 2 hours before you are exposed
ultraviolet A (UVA) light (PUVA). This treatment is
repeated 2 to 3 times a week. The dose of medicine is not increased, but the
amount of light may be increased.
Goggles should be worn to protect eyes during UVA treatment.
Special UVA-blocking glasses should be worn for 24 hours after PUVA therapy.
Men should protect their genitals from UVA exposure during treatments.
Psoralens may also be used in a form that can be put into your bath
water. This form causes greater sensitivity to UVA than the oral medicine, so
lower doses of UVA can be used.
Psoralens increase the skin's sensitivity to UV light, including
sunlight. They are used to improve the effectiveness of UV light therapy for
It is thought that PUVA therapy reduces the excess growth of skin
cells. It also weakens the immune system.
PUVA is used to treat moderate to severe psoriasis (covering more
than 20% of the skin).
PUVA is used to treat psoriasis that has not responded to creams,
ointments, or tar products used with UV exposure (phototherapy). It should be
used in the lowest doses possible. Higher doses and more exposure increase the
risk of skin cancer.
Psoralens should not be used by:
Many studies have shown that PUVA is effective in treating
When PUVA is used to treat psoriasis, short-term side effects
The most significant potential long-term effect of PUVA treatment
is an increased risk of some types of cancer.
Other long-term side effects when using PUVA to treat psoriasis
See Drug Reference for a full list of side effects. (Drug Reference
is not available in all systems.)
Psoralens applied to the skin (topical) may help to avoid some side
effects of oral medicines used for PUVA. They may be especially helpful when
psoralens taken by mouth (oral) cause severe nausea. Topical psoralens may be
used for psoriasis that affects only a small part of the skin.
Topical psoralens, such as those given in bath water, are as
effective as oral psoralens. But if the light treatments are given in a doctor's
office, a topical psoralen may be less convenient.
Complete the new medication information form (PDF)new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Puchalsky D (2011). Papulosquamous eruptions—Psoriasis. In ET Bope et al., eds., Conn’s Current Therapy 2011, pp. 823–827. Philadelphia: Saunders.
Naldi L, Rzany B (2009). Psoriasis (chronic plaque),
search date August 2007. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
January 9, 2012
Adam Husney, MD - Family Medicine & Amy McMichael, MD - Dermatology
How this information was developed to help you make better health decisions.
To learn more visit Healthwise.org
© 1995-2014 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.