Hives are perplexing since the strangely shaped reddish spots can emerge and vanish more quickly than an ex-boyfriend. According to Whitney Bowe, M.D., a dermatologist in New York, these fleeting tiny irritants are actually extremely frequent, affecting roughly 20% of people at some point. Therefore, there is a good likelihood that you may develop hives at some point in your life.
Although the cause is occasionally evident (if you are allergic to peanuts and unintentionally consume one, the welts may occur nearly quickly), it is frequently challenging to pinpoint the precise origin of hives. The good news is that, according to the American College of Allergy, Asthma, and Immunology, they often last little longer than 24 hours and can be effectively treated with antihistamines.
Here are a few explanations as to why you might have spots all over you:
1. You use specific medications.
According to Bruce Brod, M.D., clinical professor of dermatology at the Perleman School of Medicine at the University of Pennsylvania, non-steroidal anti-inflammatories (like aspirin and ibuprofen), opioids (like morphine and oxycodone), and antibiotics (like penicillin) can all cause you to break out in hives. The American Academy of Allergy, Asthma, and Immunology states that hives typically appear an hour after taking the medication.
2. You’re Stressed
Another reason to breathe deeply is that strong emotions might cause hives. Because stress weakens your immune system, you become more prone to skin problems. According to Brod, stress hives often endure a short time—less than a day.
3. You Got Really Sweaty
The World Allergy Organization states that heat-induced hives typically begin on the neck and upper chest and extend to the face, back, and limbs. These hives can be brought on by exercise, hot showers, perspiration, and worry. Bowe advises speaking with your doctor if this keeps happening to you so they can start you on an antihistamine regimen.
4. You Came Into Contact with an Allergen in the Environment
Summertime and the livin’ is itchy. Environmental factors that can spark an outbreak include sunlight, heat, cold, grass, pollen, and dust mites, says Lauren Ploch, M.D., a dermatologist in Augusta, Georgia.
5. You’re Wearing Too-Tight Clothes
“Some people will develop hives in areas where there is more pressure on the skin, such as on the bottom of their feet and underneath tightly-fitting clothing or underwear,” says Brod. He recommends resisting the urge to scratch—and wearing loose-fitting clothing. (Leave those skinny jeans at home!)
6. You Have an Autoimmune Disease
If you still have hives after an extended period of time (a month or more), an autoimmune disease may be to blame. “Lupus or thyroid disease can cause hives,” says Ploch, who adds that type 1 diabetes, Sjogren's syndrome, and celiac disease could also be to blame. Attributing hives to an autoimmune disease is often a process of elimination, though, she says, so it’s important to check in with your doctor.
7. You Ate—or Drank—Something Funky
We know it’s a total buzz kill, but alcohol and some foods can cause hives. “We see a lot of allergic reactions from food and food additives, which is where things can get confusing because it’s not necessarily the food itself,” says Ploch. Common culprits include shellfish, eggs, and nuts, while Ploch notes that azo food dyes in candy (red, yellow, and orange colors) and the sulfites in wine and deli meat can cause hives, too. If hives are issue for you, it’s important to take a careful history of what you eat so that you can avoid those triggers in the future, says Ploch.