Are you really allergic to the sun?

When you think of environmental allergens, pollen, grass and ragweed probably come to mind.

But another reaction affects up to 20% of people in the United States: an itchy rash triggered by sun exposure.

If you develop a rash after your first sunny days of spring, it may be polymorphous light eruption, or PMLE – a common reaction to ultraviolet light.

People with PMLE get a rash when their skin is exposed to UV rays in sunlight or tanning beds. The type of rash varies from person to person, but it’s usually itchy. The rash can be in the form of blisters, red bumps, or red and scaly, but the type of rash will always stay the same for each person.

Northerners are more at risk for PMLE

People who live in northern climates are at greater risk of PMLE. That’s because PMLE occurs in areas of the body that aren’t exposed to the sun during the winter, and you won’t get it on areas that are exposed to the sun throughout the year, like your face and hands. But when you start wearing V-necks and tank tops, the rash will appear in the chest area.

PMLE can affect anyone, but it’s most commonly seen in 20- to 30-year-old women and becomes persistent. If you have a family history, there’s a higher risk of having it, but it’s not a genetic condition.

Symptoms to watch for and when to see a doctor

You’ll notice an itchy rash appear as the weather becomes warmer. The rash will last for a few days and recur after your next sun exposure, but it usually gets better throughout the summer because of ongoing sun exposure. See a physician for recurrent, bothersome rashes that don't respond to sun protection.

How to prevent sun rashes

We recommend sun avoidance. If you’re going to be outside, use a physical blocker sunscreen with zinc oxide or titanium dioxide. Wear sun protective or regular clothing, such as hats and light, long-sleeved tops, to shield your body from the sun.

Treatment options

There’s no cure for PMLE, but there are successful treatment options that can work for you.

• Topical steroids – When prevention isn’t enough, our first line of treatment is with topical steroids. These prescription creams decrease the reaction and the inflammation in the skin. It can make the rash go away faster and be less itchy.
• Skin hardening – The other option is something called skin hardening with phototherapy, in which you slowly expose rash-prone areas of skin to UVB rays in the dermatology office. It’s done following a protocol in which we start very low and then slowly increase UV exposure to gradually expose your skin to the sun, so when you’re outdoors during the summer, you don’t get the rash. This approach aligns with the theory as to why our hands and face don’t get this condition. It would have to be done every year, with several weeks to a few months of buildup prior to sun exposure.
• Hydroxychloroquine (Plaquenil) – Hydroxychloroquine is an anti-malaria drug that is used in dermatology quite a bit. It can help prevent flare-ups. It takes six to eight weeks to kick in, so you’d take it at least two months before sun exposure and then throughout the summer.
• Other, emerging treatments – Biologics and Jak inhibitors medication, which block enzymes to curb inflammation, have shown promising improvement in severe PMLE that doesn’t respond to the usual treatments. The data to support these medications is limited, and more research is necessary.