Medical News Today: Is the sun good or bad for psoriasis?

People with psoriasis often notice that their symptoms tend to get better in the summer when they are more exposed to the sun. This is not a coincidence, as sunlight can be beneficial for psoriasis when it is used correctly.

Psoriasis is an autoimmune condition that causes the immune system to make too many skin cells.

These cells accumulate on the surface of the skin in patches called plaques, which can be painful and itchy. Many people turn to medicated creams, steroids, and immunosuppressants for relief.

Sunlight may be one of the easiest ways to help heal psoriasis flare-ups, but there are some misconceptions about psoriasis and sun exposure. In this article, we look at some precautions to take when exposing the body to the sun and safe ways to benefit from sun exposure.

How does sunlight help psoriasis?

Woman in sun applying sunscreen lotion to her skin.
Exposing skin to sunlight may help to reduce inflammation and scaling, easing the symptoms of psoriasis.

The sun emits ultraviolet (UV) rays, which are classified as either UVA and UVB rays. The difference between these types is in the size of the wave. Research suggests that UV rays have immunosuppressive effects, which can help reduce psoriasis symptoms.

UVA rays range from 320–400 nanometers (nm) and can reach deep into the skin. UVB rays range from 280–320 nm and only reach the top layers of the skin.

On their own, natural UVA rays are not very effective in improving psoriasis symptoms, but UVB rays are.

UVB exposure from the sun can slow down the rapid growth of the skin cells, which is one of the main symptoms of psoriasis. This may help ease inflammation and reduce scaling in people with mild to moderate psoriasis.

Sunlight has the added benefit of helping the body create vitamin D, which protects the skin and regulates its natural immunity. Vitamin D is not found naturally in many foods but is regularly added to some dairy products.

One study found that vitamin D deficiency might be common in people with psoriasis, especially in winter when sun exposure is down.

As vitamin D helps protect the skin and balance the skin’s immune response, it is essential for people with psoriasis to get enough sunlight. Dermatologists may also recommend that people with psoriasis use topical creams that contain vitamin D.

Phototherapy and PUVA therapy

Phototherapy is the process of the body absorbing UV rays to help ease psoriasis symptoms. The term is typically used to describe UV light exposure in a controlled setting, such as a dermatologist’s office.

By themselves, UVB rays are more desirable for treating psoriasis, as they help slow the growth rate of skin cells.

Doctors may also recommend a combined treatment called PUVA therapy. During this treatment, people take a drug called psoralen, which increases the body’s sensitivity to UVA rays, before being exposed to the rays.

PUVA therapy tends to be given to people who have moderate to severe psoriasis, but it may also be used on people whose psoriasis is not responding to topical or UVB treatments. PUVA is a very effective treatment for psoriasis and is used long-term to help keep symptoms from returning.

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Benefiting from sunshine safely

Peeling skin due to sunburn.
It is important to be cautious when exposing skin to sunlight, as over-exposure may cause sunburn.

When people utilize sunlight carefully, it is a helpful tool for psoriasis treatment. It is vital to start slowly, however, to reduce the chance of skin damage.

Dermatologists will recommend limiting the amount of time a person spends in the sun each day.

Even 10 minutes of full-body sun exposure allows the body to absorb sunlight while still reducing the risk of sun damage.

If the body tolerates this and the sun does not aggravate psoriasis symptoms, exposure may be increased by 30 seconds each day, up to 30 minutes.

Working directly with a dermatologist or doctor, many people can find a safe amount of time to get the benefits of the sun without damaging their skin.


When used safely, sunlight is great for psoriasis; however, too much sunlight can cause further damage to the skin.

Psoriasis is more common in light-skinned people who already have a higher risk for sunburn due to lower levels of melanin in their skin. The risk of dangerous skin cancers is also higher in light-skinned people as well, according to the Centers for Disease Control and Prevention (CDC).

People with psoriasis should avoid overexposure to sunlight and protect themselves against sunburns. Overexposure and sunburn lead to cell damage, which can cause further psoriasis flare-ups.

Tanning beds

The National Psoriasis Foundation do not recommend the use of tanning beds for psoriasis symptoms.

Unlike in phototherapy units, the wavelengths in tanning beds can damage the skin and increase a person’s risk of developing skin cancer. Tanning beds use more UVA light than UVB light, making them less effective at reducing psoriasis symptoms.

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Precautions to take

It is always important to take extra precautions whenever exposing the skin to the sun. There are a few things for people with psoriasis to consider before venturing out into the sun.


Sun lotion being squeezed from bottle into palm of hand.
Sunscreen should be applied before exposure to sunlight, even during cold weather.

Finding a good sunscreen is a crucial part of sun exposure of any kind. A broad-spectrum sunscreen may be most beneficial, as it protects against both UVA and UVB rays.

A dermatologist may recommend choosing a sunscreen with a sun protection factor (SPF) of at least 30. Higher numbers will provide more protection from sunburn caused by UVB rays.

Some people also look to water resistant sunscreens to help protect their skin while swimming or sweating under the hot sun.

For people with psoriasis, there are hypoallergenic sunscreens or sunscreens made for sensitive skin. Some chemicals in generic sunscreens can irritate the skin or cause psoriasis flare-ups.


Some medications, especially topical creams and ointments, may make the skin more sensitive to light. This could increase the risk of sunburns and skin damage.

It is important to ask a healthcare professional about any risks associated with specific medications or treatments.

Other precautions

Wearing long-sleeved shirts, hats, and pants can also help reduce exposure when spending a lot of time in the sun. It can also help to wear sunglasses, as the sensitive skin around the eyes may be more prone to damage from the sun.

Seeking shade when the sun is strongest can also help avoid overexposure. Shade from a tree, umbrella, or tent can help block some of the sun’s rays. Sunlight may also reflect off of snow or water and increase skin exposure.


There is currently no cure for psoriasis, so treatment focuses on reducing and managing symptoms. The UV rays provided by the sun and vitamin D the body absorbs from those rays can be beneficial for people with psoriasis when they have a flare-up.

Taking precautions when exposing the affected skin to sunlight can help improve symptoms over time or prevent them from getting worse.

Working directly with a dermatologist, many people can find relief from their symptoms using sunlight or phototherapy.

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