Exposing the skin to sunlight helps some people with eczema but not others. For some, the sun can trigger an eczema flare-up. People with eczema can protect their skin by seeking shade, covering up, and wearing mineral sunscreen.

Eczema is a common skin condition that causes inflammation and itchiness. It has various causes, such as allergies, stress, or environmental factors. For some people, sun exposure can improve their symptoms.

This article explains how the sun may help or harm eczema, how to protect the skin from the sun, and other tips for managing eczema when the temperature rises.

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Eczema is a chronic skin condition that can be difficult to manage. Extremes of temperature can affect symptoms, but everyone’s eczema responds differently. While some individuals have fewer flare-ups in summer, others can have worsened eczema in warmer temperatures. Below are several ways that the sun may help this condition.

Sunlight can dry out weeping skin

Exposure to the sun can be drying to the skin. This may benefit people with weeping or blistering patches of eczema but may cause problems for those with very dry patches.

Learn more about weeping eczema.

Sunlight increases vitamin D

A 2015 study found that a lack of sunlight may affect eczema development. It suggested that insufficient vitamin D, which the body makes on exposure to sunlight, has links to an increased risk of eczema. In the summer, when people are more likely to spend time in the sun, their vitamin D levels increase and eczema symptoms may improve.

Learn more about vitamin D and eczema.

Warmer temperatures may decrease stress

Another way the sun may improve eczema is by helping people feel relaxed and less stressed. Studies have found strong links between stress and eczema, although researchers do not fully understand the mechanisms involved.

Ultraviolet B (UVB) rays have proven a successful treatment

Phototherapy is successful in treating eczema for some people. It is a form of light therapy that uses UVB light to reduce itching and inflammation. Exposing the skin to sunlight, which contains UVB light, may have a similar effect on some individuals.

Learn more about phototherapy.

For many people, warmer temperatures and sun exposure can worsen eczema. Researchers have been trying to understand why some people’s eczema reacts negatively to the sun while others experience the opposite. Below are some ways that the sun may make the condition worse.

Sunlight increases the likelihood of sunburn

The sun can dry out the skin, making it more vulnerable to damage from UV rays. When the skin becomes dry and fragile, it is more susceptible to burning. According to the American Academy of Dermatologists (AAD), sunburn can cause long lasting damage to the skin and increase the risk of skin cancer.

Heat increases itchiness

The heat from the sun can cause eczema to itch more than usual, which may lead to scratching. Scratching can cause further damage to the skin barrier, leading to open sores that can contract an infection.

Sunlight can trigger flare-ups

In rare cases, sunlight can trigger a type of eczema called photosensitive dermatitis. In people with this condition, the immune system reacts to some part of the electromagnetic spectrum of sunlight. Eczema flare-ups can occur 30 minutes to several hours after sun exposure or even several days after.

Some medications can also cause a person’s skin to become more sensitive to sunlight. People can read about the side effects of medication on the product label or discuss this with a healthcare professional.

Learn more about photosensitive dermatitis.

The sun can damage healthy skin cells, especially when people spend time outside without adequate protection. The AAD recommends that in hot weather, people should seek shade between 10 a.m. and 2 p.m. when the sun’s rays are strongest. The AAD also recommends using sunscreen and covering the skin.

Sunscreen

The best skin protection is a sunscreen that offers both UVA and UVB protection. People can use sunscreens year-round to protect the skin from damaging UV rays.

Although darker skin is less likely to burn than lighter skin, the sun can still cause cell changes, leading to a higher risk of skin cancer and visible signs of damage, such as wrinkles. Therefore, it is still important for people with darker skin to wear sunscreen when the sun is strong.

People should choose a sunscreen with a minimum SPF of 30, apply it 15–30 minutes before going out, and reapply it as necessary.

Additionally, sunscreen is less effective after swimming, towel drying, or sweating, so people should reapply them every 2 hours.

There are two types of sunscreen: chemical absorbers that absorb UV radiation from the sun and mineral-based reflectors that reflect UV radiation.

Mineral sunscreens contain titanium dioxide, zinc oxide, or both. According to the AAD, they can feel cooler on the skin and may be less irritating than chemical sunscreens.

People with eczema may prefer mineral sunscreen, as it is unlikely to cause a flare-up. However, titanium dioxide can leave a white sheen on the skin, which may be more visible on darker skin.

People can test sunscreen on a small patch of skin for 24–48 hours to check for irritation before applying it all over the body.

Learn about the best sunscreens for sensitive skin.

Covering up

Having eczema can make it difficult to enjoy activities outside in the summertime. However, people can cover the skin with clothing that provides protection from UV rays. The AAD suggests wearing the following items in the sun:

  • Lightweight long-sleeved shirts and pants: These help cover up as much skin as possible. Darker colors are more protective than lighter colors, and close weave fabrics are more protective than loose weave items, such as lace.
  • Sunglasses with UV protection: A person should read the label on sunglasses carefully to ensure they offer UV protection. Wraparound sunglasses and those with large frames offer the most protection.
  • Wide-brimmed hat: Hats with wide brims prevent the sun’s rays from reaching the head, face, and neck. Some may even cast shade over the chest and shoulders.
  • Full shoes: A person should opt for a shoe that completely covers the foot. If they wear sandals or flip-flops, they should cover the exposed parts of the foot with sunscreen and reapply it every 2 hours.

Emollients are topical treatments that can help soothe dry, irritated skin. However, it is important that people using them also use sunscreen. Otherwise, the emollient may cause a “frying effect,” causing sunburn and skin irritation.

People should wait 30 minutes after applying an emollient before applying sunscreen. This prevents the emollient from diluting the sunscreen and helps it retain its protective properties. A person should never apply the products the other way around.

When applying sunscreen, people should avoid rubbing it in. This can cause itchiness in those with eczema. Instead, they should apply it in downward strokes, the same way they would apply their emollient.

Many different types of emollients are available, including mineral-based, plant-based, and synthetic options, such as petroleum jelly.

Learn more about emollients.

The most important steps a person can take to protect their skin from the sun are wearing sunscreen, covering up, and seeking shade. The National Eczema Association (NEA) also provides the following tips for managing eczema in the sun:

  • Rinse off chlorinated or salt water after each swim and apply moisturizer followed by sunscreen.
  • Rinse skin after sweating and change clothes to keep the skin clean and dry.
  • Stay hydrated by drinking 8 cups of water each day.
  • Do not wear clothing that is too tight or too loose on the body, especially when outside in the sun for long periods.
  • Take antihistamines to manage seasonal and environmental allergies.
  • Store sunscreen in a cool, dry place away from direct sunlight. Buy a new sunscreen every year.

Below are answers to some common questions about eczema and sunlight.

Is it OK to swim if you have eczema?

Swimming can be a suitable exercise for people with eczema because it helps relieve stress, which can trigger symptoms. Many individuals with the condition find that chlorinated water helps soothe their irritated skin. However, the reverse can be true for others. Likewise, salt water can improve symptoms for some and worsen them in others.

The NEA recommends showering right after swimming and applying moisturizer within 3 minutes to prevent the skin from drying out.

Can sweating make eczema worse?

Sweating is one of the most common triggers for eczema. As sweat evaporates, it dries the skin and leaves a salty residue that causes itching and irritation. People can regularly rinse sweat from the skin using clean water and wear loose-fitting natural fabrics to keep the skin cool.

For some people, the sun can alleviate eczema symptoms. However, it can worsen them in others.

The sun can damage the skin, and eczema-prone skin may be even more susceptible to damage. To protect the skin, people should stay in the shade during the middle of the day, wear sunscreen with a minimum SPF of 30, and cover the skin with protective clothing.

Individuals with eczema can still enjoy the sun by taking extra steps to apply moisturizers, keeping the skin clean and dry, and drinking plenty of water to stay hydrated.