Psoriasis Treatments: Understanding Phototherapy

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For the millions of people who have psoriasis, preparing for the change in seasons is a lot like preparing for extended deep sea diving, or for hibernating. The relief that can occur when the summer sun is present gives way to dry, heated indoor air, and months spent under heavy, irritating layers of clothing.

If you’ve suffered from psoriasis for long, you’re probably developed a winter routine that makes use of humidifiers, moisturizing creams and lotions, and other household preparations, and all of those can help keep your psoriasis under control. Phototherapy is another option, since it can help mimic the healing effects felt during the sunnier months of the year.

Scientists aren’t exactly sure how light therapy works, but some types of it have been used for nearly a century.

There are three standard types of phototherapy:

UVB (ultraviolet B)

UVB treatment uses the same type of light that that is considered the most healing wavelength derived from the natural sun. Traditionally, the treatment was administered by a photodermatologist, who would put you in goggles and other protective gear. Now, doctor-recommended lamps are also available for the home. This type of treatment is often combined with other therapies, including the Goeckerman regimen and the Ingram regimen—both developed in the early and mid 1900s. Typically patients need 18 to 30 treatments over the course of several months before they see improvement in their condition.


Two types of lasers are generally used to treat psoriasis. The excimer laser was first developed for eye surgery, but it was approved by the U.S. Food and Drug Administration to focus high-energy UVB light precisely onto small areas of skin, such as elbows, ears, and knees. This treatment is generally administered two times a week for several weeks.

Pulse Dye lasers use a different wavelength of light in order to kill red blood vessels that contribute to the development of psoriatic lesions.

PUVA (Psoralen plus ultraviolet A)

PUVA also uses a different wavelength of light to treat psoriasis. The method combines ultraviolet A light with a medication (psoralen) that makes the skin more sensitive to light. PUVA can be a good way to clear up severe psoriasis quickly, but it has some side effects such as nause, headaches, burning, itching, and fatigue. It is sometimes called photochemotherapy, and using this treatment over a period of time can increase the risk of skin cancer. This, combined with the need to wear ultraviolet-light blocking sunglasses and other precautions, make PUVA a treatment that is generally reserved for severe psoriasis, or for people who have not responded to other treatments.


For centuries people have used the combination of sunlight and saltwater to improve their health. Since the days of the prescribed “rest cure” at the seashore are (sadly) over, balneophototherapy aims to recreate the atmosphere in a clinical setting. This method utilizes a highly concentrated dead-sea brine (salt water) bath, followed by a bask under UVB light. Sometimes called “spa medicine,” this type of treatment nevertheless has been shown to improve skin condition in psoriasis patients who can attend sessions, particularly those with smaller lesions.