From sunlight to bug bites, what are the top causes of hives in summer?

Bug bites, sunlight and the heat of the season are just some of the triggers that could be causing your summertime hives.
Itching in a woman
“They tend to come on suddenly and they are incredibly itchy. People are miserable with them. They might only last a few hours then they’re gone. Or they might come back later in a different spot,” said Dr. Melissa Piliang.BSIP/UIG / Getty Images stock
By Stephanie Thurrott

Hives are itchy pink welts that could appear anywhere on the skin. Hives vary in size, and they sometimes merge together to cover large patches of your skin. Individual hives usually go away in less than 24 hours, but new ones can appear. So, you might battle a case of hives for up to six weeks, according to the American Academy of Dermatology (AAD).

“They tend to come on suddenly and they are incredibly itchy. People are miserable with them. They might only last a few hours then they’re gone. Or they might come back later in a different spot,” said Dr. Melissa Piliang, a dermatologist at the Cleveland Clinic and a member of the American Academy of Dermatology.

“For most people who have hives, the episode will end, and their skin will be better within a few days. If that’s not the case, you should see your dermatologist,” she said.

Hives are common — and anyone can get them. According to the American Osteopathic College of Dermatology (AOCD), 20 to 30 percent of people will get hives at least once in their lives.

Symptoms of hives

What do hives look like? Hive symptoms include slightly swollen, raised pink or red areas on the skin. You may see hives alone or in a group, or connected together to cover a lot of your skin. They don’t blister.

“Hives are something that by definition are going to be transient. The lesions come and go within 24 hours. If you have something hanging around for longer than that, it’s not a hive,” said Dr. Jenny Murase, associate clinical professor of dermatology at the University of California, San Francisco, and a member of the American Academy of Dermatology.

It’s rare, but possible, that your hives could cause swelling of your lips or tongue or itching in your mouth or throat. If you notice those symptoms, go to the emergency room, Piliang said. You’ll need medical care to make sure your airway doesn’t close from the swelling.

Causes of hives

It’s likely you may never know what triggers your hives. The AOCD reports that in 95 percent of people with chronic hives, there’s no identified cause.

It’s worth seeing a dermatologist for evaluation, though, because you could be in that 5 percent of people who can determine their causes for hives.

Your hives could be caused by:

  • Insect stings or bites
  • An underlying disease or condition
  • An allergic reaction
  • An overactive immune system
  • Medication
  • Foods and drinks, such as citrus fruits, milk, eggs, peanuts, tree nuts and shellfish
  • Stress
  • Sunlight
  • Pollen
  • Cold
  • Pressure
  • Vibration
  • Exercise
  • Scratching or rubbing the skin
  • Getting hot and sweaty

Sometimes you’ll notice hives right after you’re exposed to a trigger. But your reaction could also start up to two hours later, according to the AAD.

If you don’t get good results with antihistamines your doctor might recommend steroids or other medications. chokja / Getty Images stock

Diagnosing hives

To diagnose hives, your dermatologist will examine your skin and ask questions about your symptoms and possible causes. If you develop repeated cases of hives you may want to keep a symptom diary to share with your doctor. Tracking your symptoms and possible triggers could help identify the cause of your hives.

Your dermatologist may also recommend allergy tests, blood work or a skin biopsy, according to the AAD.

Treatment for hives

Antihistamines are the go-to treatment for hives, according to the AOCD. But there are some key factors to consider.

The AOCD says it’s important to:

  • Find an antihistamine that’s strong enough
  • Use the right dosage
  • Continue the antihistamine for long enough to ward off future outbreaks

“A mistake people will make is they take antihistamines for a few days and then they go off them, and it starts up again,” Murase said. “What you want to do is shut the cycle down — take enough antihistamine so it quiets.”

If you don’t get good results with antihistamines your doctor might recommend steroids or other medications.

You can alleviate the itching from hives with an ice pack. “Cold and itch run on the same nerve pathways — you can’t feel both at the same time,” Piliang said. “So if the hives are super itchy, putting an ice pack on them can help.”