For some people, over-the-counter or prescription creams are enough to keep psoriasis under control. But if your skin remains itchy, scaly, and red, you can try phototherapy, which is also called light therapy.

Phototherapy is a type of psoriasis treatment that may make the pain and itchiness of the condition go away. Ultraviolet light reduces inflammation and slows down the creation of skin cells. It’s also used for other skin conditions such as eczema. But it’s not as simple as just going out in the sun.

A variety of different types of ultraviolet light treatment exist. If you’re interested in trying this approach, the key is to determine what 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.

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, which can affect this treatment.

Phototherapy is considered safe for children and people who are pregnant.

Your doctor will adjust how much light you get based on the severity of your psoriasis. Your skin type — how dark or light your skin is — also makes a difference in the amount of light used.

This treatment can make your skin sore and red, leave blisters, or 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.

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

That’s because tanning beds use UVA, which doesn’t help psoriasis unless used with certain medications. Moreover, use of these machines carries a much higher risk of skin cancer than medically supervised treatments.

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

These are the main light therapy options:

UVB light

Narrowband UVB is the most common form of phototherapy. In the past, doctors used a similar therapy called broadband UVB, which has slightly longer UV wavelengths. But now organizations such as the National Psoriasis Foundation recommend narrowband because it’s more effective and less likely to cause burns.

A 2016 guide to phototherapy created by researchers from the University of California says a trial of broadband UVB is an option for people who don’t respond to narrowband UVB.

In a course of treatment using narrowband UVB, a doctor will provide the therapy three to five times a week for about three months. A treatment typically costs about $130 out of pocket, according to Windsor Dermatology in New Jersey. It’s often covered by Medicaid and Medicare, as well as many private insurance policies.

You may start to see results in two weeks. If your symptoms return after a course of treatment, you can usually choose to have more. A 2017 study published in PLoS One found that 75 percent of people receiving narrowband UVB treatments found it cleared their psoriasis or led to minimal symptoms, and they used fewer prescription creams for their condition, too.

Laser UVB

This treatment is similar to narrowband UVB therapy, but it’s given via a laser — often an excimer laser — on small areas of your body. If you have psoriasis over less than 5 percent of your body, this treatment might work for you. This approach exposes you to fewer UV rays, which will reduce side effects and health risks.

You usually get two to three treatments a week and can start to see symptoms improve after 10 sessions. This is a more expensive option, running about $600 per treatment out of pocket, but some insurance policies will cover it.

PUVA therapy

This approach uses UVA light with a medicine called psoralen that you take via a pill or cream. Psoralen increases how sensitive you are to light. This treatment is aimed at people with moderate to severe psoriasis and works best on plaque and guttate types of psoriasis.

Home therapy

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. And you still need see a dermatologist regularly to monitor your skin and get advice on using your home device.

Lamps designed for psoriasis start as low as $250 online, but many higher-end products cost $2,000 or more. Your insurance may help with the purchase price.

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’s more UV 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 progress you time of exposure to the sun, starting with only about 5- to 20-minute periods.

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

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