What is UVB therapy?
Ultraviolet B band (UVB) phototherapy is the treatment of psoriasis by exposing the skin to specific wavelengths of ultraviolet light, which are found naturally in sunlight and are the most biologically active wavelengths of ultraviolet radiation and have the potential to produce sunburn. UVB can be artificially generated by phototherapy light boxes for the treatment of psoriasis.
UVB therapy needs to be performed in a medical setting under the direction of a physician. UVB devices used by physicians can produce intense therapeutic effects. UVB devices designed for medical use are usually different from those used at home. They are also different from those used in tanning salons (see “What is the difference between UVB and UVA?” at the end of this brochure). .
In this brochure, the term “UVB” refers to the most common type of UVB phototherapy used in the United States. There is another type of UVB treatment called “narrow band UVB”.
You can learn more about phototherapy by requesting the NPF brochures “Home Phototherapy” and “Psoriasis and Sunlight”.
Who is a candidate for UVB therapy?
UVB therapy can be used in adults and children. UVB can be used in at least two-thirds of patients with the following indications.
1. thin plaques (reduced scaling production).
2, moderate to severe disease.
3. susceptibility to react to natural sunlight.
UVB may be considered when topical treatments have failed, either alone or in combination with topical treatments (corticosteroids, anthralin, coal tar) or systemic drugs (oral retinoids or methotrexate).
UVB is the standard of care for moderate to severe psoriasis. Moderate to severe psoriasis can involve any part of the skin from 2% to 100% of the body (the palm of the hand is roughly equivalent to 1% of the body surface area).
UVB can take a considerable amount of time. Patients will only get the best results if they keep their appointments and follow instructions. As with all treatments, UVB requires a time and energy commitment.
How is UVB treatment performed?
Patients stand in a treatment light box with special UVB lamps installed, or within one or more rows of lamps. Some doctors have small units for treating limited areas such as the palms of the hands and soles of the feet.
Patients are usually treated three times a week. Clearing psoriatic lesions requires an average of thirty treatments. The patient removes clothing to expose all affected areas to UV light. However, the following things need to be noted.
1. Protect the male genital (groin) area with cloths, paper or sports pads.
If the genital area is involved, the area is allowed to be exposed to UVB for a short period of time. Other methods of treating psoriasis in the male genital area are also available. Female genitalia do not require special protection.
2. Eye protection.
Goggles, gogglets and special sunglasses that tightly cover the area around the eyes and are designed to block UVB lines provide the best protection. With ordinary sunglasses some of the light can still pass through to reach the eyes.
l. What is UVB treatment like?
The first light exposure is usually very short, lasting as little as a few seconds. The duration of exposure depends on the patient’s skin type (see Figure 1) and the intensity of the light emitted by the bulb used. The lighter the skin tone, the more sensitive people are to UVB. They start with a lower exposure time than people with darker skin.
In general, the number of treatments should be gradually increased until the lesions begin to clear, unless the final interval produces itchy and/or tender skin. Because precise quantification of UVB phototherapy cannot yet be made, the response of each patient is not completely predictable. Subsequent treatment regimens should be adjusted appropriately based on each patient’s response.
Skin Type
There are six skin types recognized by the FDA and the American Academy of Dermatology.
Type I – Always burns easily, never tans, extremely sun-sensitive skin; redheaded, freckled, Celtic Irish-Scots.
Type II – always burns easily, can be slightly tanned, very sensitive to the sun; fair-skinned, blue-eyed whites.
Type III-Sometimes burns easily, can gradually tan to tan; sun-sensitive skin, average skin.
Type IV-can be slightly burned, always tans easily to light brown; mildly sensitive to sunlight, Mediterranean ethnic skin type, white.
Type V-rarely burned, tanned, sun-sensitive skin; people from the Middle East, some Hispanics, some blacks.
Type VI-never burned, heavily pigmented; sun-insensitive skin, blacks.
Some treatments can be used in combination with UVB. Topical treatments such as anthralin and vitamin D3 derivatives (Darex, Dovonex) and a derivative of vitamin A (Tazorac) are effective in combination with UVB in some patients. In addition, UVB improves response to UVB when used in combination with some systemic treatments including methotrexate and oral retinoids (Avelox).
Many physicians use topical corticosteroids in combination with UVB, but there is evidence that topical steroids in combination with UVB may lead to shorter remission intervals. Discuss with your doctor whether this combination therapy is appropriate for your psoriasis condition.
The physician should ask the patient to complete one or more of the following prior to UVB treatment.
1. tell the provider what medications you have used or are using, both topical and oral.
2. soaking in warm water for 30 minutes to remove psoriatic scales
3. protecting clean areas of skin with sunscreen (e.g., backs of hands, neck, lips, nipples and darkly pigmented areas of the breasts).
4. covering uninvolved areas of the body such as the face with paper, cloth or sunscreen to avoid unnecessary exposure to light.
5. pre-applying tar the night before the treatment and rinsing them off the morning of the treatment.
Some studies have shown that mineral oil or petroleum jelly oil is as effective as tar or anthralin when used in combination with UVB. A thin layer of mineral oil or petroleum jelly applied prior to treatment improves the ability of the light to penetrate the skin.
Any other topical items left on the skin may block some or all of the UVB light, thus reducing the effectiveness of the treatment. This is especially true of tar, salicylic acid and thick wetting agents.
How effective is UVB?
When used correctly, UVB is usually very effective, with most patients clearing lesions and getting significant improvement. In one study, over 90% of patients had complete clearance of lesions. However, the key to maximum efficacy is patient compliance: the best results can only be achieved by attending all appointments on time (usually at least three times a week) and following treatment instructions.
What to do when the lesions are cleared?
Once the lesions have cleared, treatment can be stopped. They can be restarted when the lesions return. Sometimes UVB treatment can be continued with maintenance doses. Studies have shown that UVB maintenance therapy can prolong remission. One study showed that maintenance therapy as little as six times a week extended remission by at least six weeks. Most patients require maintenance therapy approximately eight times per week to prolong remission, but this varies from person to person.
When psoriasis lesions return, patients may need to increase the frequency of treatment. Sometimes the treatment can be changed to another treatment. Changing treatment gives the skin an interval of UVB, reducing the side effects of prolonged UVB exposure. Also, those patients who require prolonged exposure may have fewer treatments after a UVB interval.
NPF’s “Home Phototherapy” brochure explains the benefits and limitations of home treatment and lists the various manufacturers of home phototherapy devices. These devices range from tabletop models to full-body treatment kits.
What are the side effects of UVB?
During treatment, psoriasis may worsen transiently before improvement is obtained. Itching and redness of the skin may occur due to UVB exposure. To avoid further irritating effects, the amount of UVB exposure should be reduced. Occasionally, transient episodes of psoriasis may occur with exposure levels that do not cause burning. These reactions can be eliminated with continued treatment with UVB.
If tar is used in combination with UVB, the skin pores may become blocked and small pimple-like papules (folliculitis) may appear. These rashes are due to improper tar application. Tar application should follow the direction of hair growth. Folliculitis does not persist, but occasionally tar application needs to be discontinued.
Natural light exposure should be avoided during UVB treatment. Excessive UVB exposure may cause severe burns. Wearing clothing or using sunscreen is recommended. UVB should not pass through the glass of windows.
What are the long-term risks?
Long-term risks of UVB from sunlight include premature skin aging and skin cancer. Long-term exposure to UVB from sunlight may also produce blemishes, loss of skin elasticity and the appearance of folds. Some of these symptoms are partially reversible.
The exact risk of skin cancer due to prolonged exposure to UVB therapy is not known. UVB is a definite carcinogen (cancer-producing substance or drug) in humans, but long-term studies have shown that the risk is small in UVB phototherapy. Some studies have shown that patients treated with UVB have no increased risk of skin cancer compared to the normal population. However, the treatment still needs to be used with caution to avoid other effects on the skin.
When evaluating the risk, it should be noted that skin cancer is generally easy to remove if it is detected early. It is important to have your skin checked regularly by your doctor.
Some doctors recommend the use of sunscreens on uninvolved skin as a way to reduce UVB exposure. The face, for example, is often exposed to a lot of natural sunlight. UVB exposure should be avoided if there is no psoriasis on the face. If extensive psoriasis is present, the use of sunscreens is impractical, but it is a useful preventive measure for moderate or localized lesions.
Some individuals need to be recommended for hospitalization or a day treatment program of intensive UVB and coal tar treatment. This requires daily treatment with coal tar (a prescription tar) and UVB for three to four weeks. This is called Goeckerman [Gek-er-man] therapy. It has been the mainstay of treatment for severe and difficult-to-control psoriasis since the 1920s.
Whether inpatient or day treatment protocols, Goeckerman therapy requires the use of natural tar on the skin. Excess tar is removed once or twice a day and the entire body is exposed to UVB. A cleansing bath or shower is then performed to remove residual tar and scales, and new tar is applied.
This treatment can be supplemented with steroid medication and keratinolytics (medications that remove thick scales), especially in the early stages of treatment. In a modified version of the Goeckerman treatment, tar is replaced with a potent topical anthralin (this is called Ingram therapy).
The duration of remission and the relative safety of Goeckerman therapy are the main reasons for its long-term use in the treatment of moderate to severe psoriasis.
Low-intensity tar and UVB therapy used in the physician’s office is often used as a modified form of Goeckerman therapy.
Day treatment or inpatient treatment?
Sometimes psoriasis is too widespread to be treated effectively in a doctor’s office, but hospitalization is not necessary. A psoriasis day treatment program provides an intermediate solution. To be included in a day treatment program patients must.
1. be able to walk without assistance.
2. be free of some health problem that could complicate treatment
3. be able to consistently travel to and from the treatment center every day for three to five weeks
4. return home or go to other boarding places in the evening and on weekends.
There are a few psoriasis day treatment programs in the United States. The best way to access such programs and services is to request the NPF’s Physician Resource Directory to find a doctor in your area who can provide tar and UV treatments.
However, even if a day treatment program is available, intensive inpatient (residential) Goeckerman therapy may still be necessary for some people. Sometimes the patient’s mood needs medical control as much as the physical condition. Bed rest and removal of the stresses of daily life are important adjuncts to inpatient Goeckerman therapy.
It is used as the main representative. The main difference between broad and narrow band is that they emit different wavelengths of UVB light; the concentrated band of narrow band units is considered the most therapeutic for psoriasis in the UVB spectrum.
Narrow-band UVB
Several studies have shown that narrow-band UVB clears psoriasis faster and provides longer periods of remission compared to broad-band UVB. Three treatments per week are effective, whereas in some cases broadband UVB requires more frequent treatments to be effective. Narrow-band UVB has also been developed as an alternative to PUVA (photosensitizing drug psoralen plus UVA exposure). Although not as effective as PUVA, narrow-band UVB is more acceptable and appears to have less long-term risk.
Narrow-band UVB is the most widely used type of phototherapy in Europe, but it has yet to receive widespread attention from physicians in the United States. As doctors and patients learn more about its effectiveness, use and safety, and as device costs decrease, the use of narrow-band UVB will gradually increase.
UVB and UVA: What’s the difference?
Many people ask about the difference between UVB (a type of light typically used in phototherapy) and ultraviolet A (UVA). Because UVA is used not only in doctors’ offices but also in commercial tanning salons, there is a natural curiosity about its possible role in the treatment of skin diseases such as psoriasis.
UVA itself is not used as a routine treatment to clear psoriasis unless the patient is also treated with a photosensitizing drug such as psoralen. The combination of psoralen and UVA is called PUVA.
Doctors use UVB because it has been shown to be the most effective and least dangerous type of phototherapy. Treating psoriasis in tanning salons can be dangerous because the personnel are not medically trained and the effectiveness of phototherapy devices can vary greatly.
Many doctors caution their psoriasis patients against going to tanning salons, saying they are ineffective and can be dangerous. They consider UV therapy to be a treatment that needs to be supervised by a physician.