For some people, over-the-counter or prescription creams are enough to manage psoriasis. However, if your skin remains itchy, scaly, and red, you can try phototherapy. It’s also known as light therapy.

Phototherapy is a type of psoriasis treatment that may make the pain and itchiness of the condition go away. It often uses ultraviolet (UV) light, which reduces inflammation and slows down the creation of skin cells.

Phototherapy is also used for other skin conditions, such as eczema. However, it’s not as simple as just going out in the sun.

A variety of different types of UV light treatments exist. If you’re interested in trying this approach, the key is to determine which one will work best for you.

To be safely treated with phototherapy, it’s best to talk to your doctor about your options. Your doctor will make sure it’s safe for you.


Phototherapy is considered safe for both children and women who are pregnant.

If you’re ready to try phototherapy, consider which treatment will be best for you. Your doctor may recommend combining UV therapy with a prescription cream.

Narrowband ultraviolet B (NB-UVB) light therapy

Narrowband ultraviolet B (NB-UVB) is the most common form of phototherapy. It can be used to treat plaque or guttate psoriasis.

NB-UVB lamps and light bulbs emit wavelengths of light between 311 and 313 nanometers (nm), according to recent clinical guidelines on phototherapy.

Your starting dose will depend on your skin type and how easily you burn or tan.

However, NB-UVB light therapy is most effective when performed two or three times a week. An emollient such as petroleum jelly may be applied before each session.

According to a 2002 study, people who had twice-weekly sessions saw their symptoms clear up in an average of 88 days. Those with sessions three times a week saw their symptoms clear up in an average of 58 days.

Once the skin is clear, maintenance sessions can be performed on a weekly basis.

A 2017study showed that around 75 percent of people receiving NB-UVB treatments found it cleared their psoriasis or led to minimal symptoms. They used fewer prescription creams for their condition, too.

NB-UVB treatments may prove more effective when combined with topical treatments, such as vitamin D analogues and corticosteroids.

Broadband ultraviolet B (BB-UVB) light therapy

Broadband ultraviolet B (BB-UVB) light therapy is an older form of phototherapy than NB-UVB. The two treatments are similar.

However, BB-UVB lamps and light bulbs emit wavelengths of light between 270 and 390 nm.

As with NB-UVB, your starting dose will depend on your skin type.

According to a small 1981 study, 90 percent of people had clear skin after having sessions three times a week and an average of 23.2 treatments.

One hundred percent of people had clear skin after having sessions five times a week and an average of 27 treatments.

BB-UVB is considered less effective than NB-UVB and is more likely to cause side effects. It should be reserved for instances where NB-UVB isn’t a treatment option.

BB-UVB is most effective for plaque psoriasis, although it can also be used for guttate psoriasis.

It can be prescribed as a monotherapy or alongside retinoid acitretin (Soriatane). In combination therapy, the skin clears up faster, and lower doses of UVB can be used.

Targeted ultraviolet B (UVB) light therapy

Targeted ultraviolet B (UVB) light therapy is applied to small areas of the body. It often involves the use of an excimer laser, excimer light, or NB-UVB light.

If you have psoriasis over less than 10 percent of your body (known as localized psoriasis), this treatment might work for you.

This approach exposes you to fewer UV rays overall, which will reduce side effects and health risks. It also results in faster clearing of the skin.

For best results, it should be performed two to three times a week.

Targeted UVB therapy can be used to treat:

  • plaque psoriasis
  • scalp psoriasis
  • psoriasis on the soles or palms (palmoplantar psoriasis)

Excimer lasers are more effective than excimer lights or targeted NB-UVB lights. Adults with plaque psoriasis can combine excimer laser therapy with topical corticosteroids.

Psoralen plus ultraviolet A (PUVA) therapy

This approach uses ultraviolet A (UVA) light with psoralen, a medication that increases your sensitivity to light. Psoralen can be:

  • taken orally
  • mixed in bathwater
  • applied topically

In general, PUVA is highly effective but not widely used or available.

Oral PUVA comes with the highest risk of drug interactions and side effects (such as nausea). It’s most effective when combined with an oral retinoid.

Bath PUVA works best for adults with moderate to severe plaque psoriasis.

It’s performed more often in Europe than in the United States. This is primarily because it uses trimethylpsoralen, a form of psoralen that the Food and Drug Administration (FDA) hasn’t approved.

Topical PUVA may be of particular benefit to adults with palmoplantar psoriasis or palmoplantar pustular psoriasis. It can also be used for localized psoriasis.

Other types of phototherapy that either aren’t as effective, widely recommended, or widely used are described below.

Sunshine therapy

You can also go outside and expose the areas of your body affected by psoriasis to the sun’s UV rays. This works best from May to October when there are more UV rays coming from the sun.

If you live farther south, that period is even longer.

You need to cover your unaffected areas with sunscreen and slowly increase your time of exposure to the sun. Start with periods of only 5 to 20 minutes.

This treatment might take longer to work than a UV lamp, and it also increases your risk of skin cancer. You should only use this approach with your doctor’s support and guidance.

Tanning beds

Be aware that tanning salons are no substitute for doctor-supervised light therapy. The National Psoriasis Foundation (NPF) reports that tanning devices can’t stand in for phototherapy treatments.

That’s because tanning beds use UVA, which doesn’t help psoriasis unless combined with certain medications.

Moreover, the use of these machines carries a much higher risk of skin cancer than medically supervised treatments.


Climatotherapy is relocation, either temporary or permanent, to a place with a more suitable climate as well as natural resources that can be used for symptom relief.

These favorable locations include:

  • the Dead Sea (with its low altitude)
  • the Canary Islands
  • Iceland’s Blue Lagoon

Climatotherapy typically involves components such as:

  • consultations with medical professionals
  • a personalized sun schedule
  • psoriasis education

Although people practicing climatotherapy typically see improvements in their skin and mental health, some research shows that the positive effects tend to fade after a few months.

Studies are needed on remission.

Goeckerman therapy

Goeckerman therapy combines coal tar with UVB light therapy. It’s used for people with severe or recalcitrant psoriasis. Recalcitrant disease is resistant to treatment.

It’s highly effective but rarely used, in part because of its messiness.

Pulsed dye laser (PDL) therapy

Pulsed dye laser (PDL) therapy may be used for nail psoriasis.

A 2014 study found that monthly PDL treatments were more effective than twice-weekly excimer laser treatments.

PDL causes only mild side effects.

Grenz ray therapy

Grenz ray therapy uses radiation. A typical treatment plan consists of weekly sessions for four or five times, a 6-month break, and then up to 6 more months of treatment.

Research on it is limited. A small survey found that only around half of respondents deemed it useful. It may be recommended for people with recalcitrant psoriasis that hasn’t responded to other treatments.

Visible light therapy

Visible light therapy may use blue or red light. Small studies have shown promise, but more research is needed.

A version of visible light therapy known as intense pulsed light (IPL) therapy has led to great results when used in the treatment of nail psoriasis.

Hyperpigmentation is common, but side effects are generally minimal.

Photodynamic therapy (PDT)

In PDT, photosensitizing agents (such as acids) are applied to the skin. When activated by blue or red light, these photosensitizing agents can help destroy premalignant or malignant cells.

Research has shown that the risks, which include severe pain, typically outweigh the benefits. One literature review found that only 22 percent of people saw a noteworthy reduction in disease severity.

It’s more effective at treating nail psoriasis than palmoplantar psoriasis or other types of localized psoriasis. However, experts don’t currently recommend it for any form of the disease.

For best results, you should undergo at least 20 phototherapy sessions, according to a 2016 study.

PUVA is the most effective of the major forms of phototherapy, with some studies showing that over 70 percent of people who received oral PUVA achieved a PASI 75.

PASI 75 represents a 75 percent improvement in the Psoriasis Area and Severity Index score.

It’s followed by NB-UVB and targeted UVB therapy.

While BB-UVB can still relieve your symptoms, it’s the least effective of these four. Most BB-UVB studies have resulted in around 59 percent of people achieving a PASI 75.

Despite the fact that PUVA is more effective overall, NB-UVB is generally recommended instead because it’s less expensive, easier to use, and causes fewer side effects.

To boost its effectiveness, NB-UVB is often used with additional medications.


A 2013 literature review found that oral administration of PUVA is more effective than bath PUVA.

In terms of targeted UVB therapy, excimer laser is the most effective administration method, followed by excimer light and then targeted NB-UVB light.

The most appropriate therapy will also depend on which type of psoriasis is being treated. For instance:

  • Topical PUVA is the preferred treatment method for palmoplantar psoriasis, although BB-UVB has been proven effective.
  • Targeted UVB therapy with excimer lasers is the preferred treatment method for adults with scalp psoriasis.
  • PDLis the preferred treatment method for nail psoriasis.

Certain people shouldn’t try light therapy. This includes people with lupus, a history of skin cancer, or the skin condition xeroderma pigmentosum, which makes people very sensitive to sunlight.

In addition, certain medications — including some antibiotics — make you sensitive to light. Light sensitivity can affect this treatment.

Phototherapy can:

  • make your skin sore and red
  • leave blisters
  • change the pigment of your skin

It increases your risk for certain types of skin cancer, so your doctor will watch for warning signs during and after treatment.

The different forms of phototherapy, climatotherapy aside, also come with their own unique risks:

  • BB-UVB. BB-UVB increases your risk of genital skin cancer, so genital shielding is recommended. Eye protection, such as goggles, is also recommended. Practice caution if you have a history of skin cancer, arsenic intake, or exposure to ionizing radiation (such as X-rays). Arsenic and ionizing radiation are both carcinogenic.
  • NB-UVB. This therapy can cause the same side effects as BB-UVB, although they’re less likely to occur with NB-UVB.
  • Targeted UVB therapy. Common side effects include redness, blistering, burning, itching, hyperpigmentation, and swelling.
  • Oral PUVA. Risks of oral PUVA include phototoxicity, nausea, and itching. It’s not recommended for children under 10 years old, women who are pregnant or nursing, or people with certain skin conditions. Older children should practice caution if they take immunosuppressive medications, have had certain skin conditions, or have been exposed to carcinogens.
  • Bath PUVA and topical PUVA. These methods may also cause phototoxicity.
  • Sunshine therapy. Sunshine therapy increases your risk of skin cancer.
  • Tanning. The use of tanning beds carries a much higher risk of skin cancer than medically supervised treatments.
  • Goeckerman therapy. The coal tar used in this form of phototherapy may cause skin burning.
  • PDL. Side effects are mild and may include hyperpigmentation of the cuticles, minor pain, or small spots known as petechiae.
  • Grenz ray therapy. If not administered properly, it can cause painful marks. This side effect is known as radiation dermatitis or radiation burns.
  • Visible light therapy. Side effects are mild, and hyperpigmentation is the most common one.
  • PDT. Side effects are common. They include burning sensations and severe pain.

Home NB-UVB phototherapy is recommended for certain people with plaque psoriasis as an alternative to in-office NB-UVB phototherapy. It can be used for mild, moderate, or severe disease.

Many people who use phototherapy as a long-term treatment like the ease and lower cost of doing it at home.

You usually have a few rounds of in-office therapy first to make sure it works. You still need to see a dermatologist regularly to monitor your skin and get advice on using your home device.

A 2009 Dutch study was the first randomized controlled trial to compare the treatments.

The researchers concluded that home NB-UVB phototherapy and in-office NB-UVB phototherapy are equally effective and result in similar side effects.

Study participants who used home treatments had a slightly higher chance of developing severe redness. Those who used in-office treatments had a slightly higher chance of blistering and burning.

Most data shows that phototherapy typically costs a few thousand dollars a year.

Medicaid and Medicare — as well as many private insurance policies —often cover in-office treatment.

At-home treatments are less likely to be covered by insurance. A standard at-home NB-UVB unit costs $2,600 on average. Bulbs will need to be replaced every 3 to 6 years.

Start-up costs for at-home treatments are more significant than those for in-office treatments.

However, after the initial equipment has been purchased, at-home phototherapy has a lower per-treatment cost than in-office treatment.

A small 2018 studyestimated that the 3-year cost of at-home phototherapy was $5,000. In addition to the lamp itself, this estimate also factored in the cost of a warranty, shipping, setting up the lamp, and technical support.

It didn’t factor in the cost of co-payments and doctor’s visits.

Some 2012 research found that adults undergoing phototherapy had yearly costs of $3,910.17.

By comparison, most biologic treatments cost tens of thousands of dollars per year.

If you’re interested in phototherapy as a treatment option, talk to your doctor to find out if you’re a good candidate.

Also, see how much your health insurance will cover and take care to budget accordingly for this effective but sometimes costly treatment.

Make sure you discuss the risks and benefits with your doctor when deciding if the treatment is right for you.