Summer brings along new challenges for people who have chronic hives. Also known as chronic urticaria, the condition can cause itchy, raised welts for 6 weeks or longer, according to the American Academy of Dermatology Association.

People don’t always know what causes their hives, but the condition can be aggravated by common summertime triggers, such as sunshine, heat, pollen, and sweat.

That doesn’t mean you have to miss out on all the summer fun, though. Read on to learn about why skin rash flare-ups can happen in the warmer months, along with tips for managing chronic hives during the summer.

Between heat waves and high pollen counts, summer has lots of potential triggers for hives. Here are a few ways to reduce the risk of flare-ups this time of year:

Learn your triggers

Hives can be triggered by a range of different things. Understanding what aggravates your hives gives you the opportunity to reduce your exposure to those triggers.

However, it can be hard to narrow down exactly what might be causing your hives. Specialists, like allergists and dermatologists, can help rule out or treat underlying conditions that may cause hives.

They can also help you find out why you get hives in the summer and recommend targeted treatments for you to manage flare-ups.

Track when you get hives

Keeping a journal about when you get hives can help you narrow down the type and whether certain things during the summer are triggers.

For example, if you notice that you often get hives within minutes of spending time outside on a bright, sunny day, you may have a rare type called solar urticaria. Likewise, people with cholinergic urticaria get hives when they sweat.

Your journal can help you to see whether your hives might be because of heat, light, or another cause.

Stay cool and dry

Avoid spending prolonged periods of time in hot and humid environments where you may start sweating.

Wearing antiperspirant can help reduce how much you sweat. You might also want to keep a soft cloth handy to dab off moisture when you start to sweat.

If you want to spend time outdoors, try to avoid the hottest times of the day. It might be more comfortable to take that beach walk in the early morning or late evening when the summer sun causes less heat than in midday.

Drink plenty of fluids

Hydration can help keep you cool and reduce the chances of hives from an elevated body temperature. This is especially important during the summer, when many people are more active, and they get dehydrated more easily.

Staying hydrated helps maintain this balance, so you may reduce your chances of a summer hives flare.

Wear sunscreen

Solar urticaria is when you get hives after exposure to visible light and UVA/UVB rays. Wearing a sunscreen that specifically blocks the type of light that causes your symptoms can help reduce your hives.

The British Association of Dermatologists recommends using one with titanium oxide or zinc oxide, which protect your skin from UVA, UVB, and visible light.

If you have sensitive skin, consider using a hypoallergenic or natural sunscreen.

Reapply sunscreen every 2 hours, or more frequently if you’re sweating or swimming.

Wear loose-fitting clothes for coverage

What you wear can make a difference in your summer hives. Loose, flowing clothes can prevent irritation and overheating.

Long sleeves and pants help protect your skin from the sun. They also create a barrier between you and grasses and plants that may cause hives.

Use cold compresses

Cold temperatures can reduce the inflammation that aggravates hives. Placing cold compresses against your skin if it starts to itch can offer some relief from symptoms.

However, if you have cold urticaria (a type of hives caused by exposure to low temperatures), avoid placing anything too chilly against your skin.

Limit pollen exposure

Pollen is a common allergen that can trigger hives in some people during the summer.

Avoid spending time outdoors when pollen counts are high. You can find out the pollen counts through local weather reports.

Some strategies can be used to help with hives all year long, including the summer. Here are a few other ways to manage hives:

  • Reduce stress. Stress can cause hives to flare up. Meditation, getting enough rest, and making time for your favorite activities can help lower your stress levels.
  • Take vitamin D. While further study is needed, there may be a link between low vitamin D levels and chronic hives. A 2018 review of studies found that people with chronic spontaneous urticaria had significantly lower than average vitamin D levels. Talk with your doctor about getting your vitamin D levels tested and whether a supplement may help your hives.
  • Take antihistamines. About 50 percent of people with hives can get relief by taking antihistamines, according to the American Academy of Allergy, Asthma, and Immunology. Some antihistamines are available over-the-counter, while others require a prescription. Talk with your doctor about which type may be right for you.
  • Get treatment. If antihistamines don’t relieve your hives, you might need another type of medication. Omalizumab (Xolair) is approved by the Food & Drug Administration to treat chronic idiopathic urticaria. A 2013 study found it was effective in some people with urticaria for whom antihistamines didn’t work. You can speak with your doctor about prescription medications that might help you with chronic hives.

It can take time to discover the best ways to manage hives, but many people find relief by avoiding triggers and working with a doctor on treatment options. Since hives can go away before your appointment, take pictures of your symptoms to show your doctor to help with the diagnosis.

Chronic hives can be categorized by their specific triggers. Some types may have more frequent flares in the summer, simply because there are more triggers in the environment that time of year.

  • Cholinergic urticaria, or heat urticaria, is caused by raised body temperature and sweating. Activities that cause you to sweat, such as being outside on hot days or vigorous exercise, can bring on a flare.
  • Solar urticaria is caused by exposure to sun or ultraviolet light. The hives appear within a few minutes of being in the sun.
  • Cold urticaria is caused by sudden cold temperatures. Many people experience cold urticaria in the winter, but even some summer activities can trigger hives in people with this condition. These include swimming in a cold pool, experiencing a sudden cold breeze, or getting a burst of air conditioning when you head indoors.

Chronic hives can also have other triggers, like certain plants, foods, or animals. Taking summer hikes near plants and grasses you don’t see much in the winter can bring on hives.

The summer months also bring on higher counts of airborne pollen and mold spores, which worsen nasal allergies and asthma. Allergies and asthma can also have an effect on the skin and may trigger hives.

Many people never find out the cause of their hives, even if they’re chronic. In fact, a 2011 study found that 75 percent of people with hives have the idiopathic version. That means it has no known cause.

A doctor may be able to help you narrow down your potential triggers over the long term, but there’s a chance you’ll never know what causes your hives. Regardless, there are treatments that can ease your symptoms and help you find relief.

Summertime weather and activities can cause chronic hives to flare in many people. You may notice rashes after sweating, spending time in the sunshine, or being exposed to pollen.

Limiting exposure to your triggers can help reduce your symptoms. However, many people have chronic idiopathic urticaria, which means the hives have no known cause. That means you may not be able to avoid the things that cause your flares.

Fortunately, treatments are available to help you find relief. Talk with your doctor about whether antihistamines or prescription medication is right for you.