What are hives? A dermatologist explains
Hives are one of those things that you hear about so often that it feels like you should know what they are, how to spot them and how to treat them. But the truth is that many of us don’t really know that much about this itchy rash. Hives are quite common, though, so it’s a good idea to get familiar with them.
Hives, or urticaria, are itchy pink welts that could appear anywhere on your skin. Some are bumps as small as a pinhead, while others may merge together to cover large patches of your skin. That means that what may appear to be one giant hive could actually be several smaller ones.
Anyone can get hives. According to the American Osteopathic College of Dermatology, 10-20% of people will get hives at least once in their lives.
Individual hives usually go away in less than 24 hours, but new ones can appear. The cycle can repeat, and 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 AAD.
There’s good news, though. It’s true that breaking out in hives is an uncomfortable experience, but hives are temporary. “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.
What are the symptoms of hives?
What do hives look like? They may look a bit different on everyone. On white skin, hive symptoms generally include slightly swollen, raised pink or red areas, and if you press on a hive, the pink or red color will disappear briefly. On brown or black skin, hives may be raised areas that are the same color as the skin, or slightly lighter or darker.
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, assistant 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 your lips or tongue to swell or your mouth or throat to itch. 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.
What causes hives?
It’s likely you may never know what triggers your hives. For 95% of people who experience chronic hives, there’s no identified cause, according to AOCD.
It’s worth seeing a dermatologist for evaluation, though, because you could be in that 5% of people who can find out what’s causing their hives.
Your hives could be caused by:
Insect stings or bites
An underlying disease or condition
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 hives will appear right after you’re exposed to a trigger. But your reaction could also start up to two hours later, according to the AAD.
Does stress cause hives?
There's also some evidence to suggest that there's a relationship between hives and stress. A 2018 study found that people who experience chronic breakouts of hives also have higher rates of stress. And a 2020 study reported that for many people with chronic hives, their symptoms started soon after a significant stressor.
But scientists are still trying to understand the relationship between hives and stress. A 2020 study suggested that there may be a connection between high levels of stress and inflammatory skin responses.
That doesn't mean that stress will necessarily cause hives in everyone, though. The link between hives and stress is strongest for people who have autoimmune conditions or have other allergy issues and are predisposed to getting hives.
But, let's be honest, it can be stressful to break out into itchy rashes, and unfortunately high levels of stress can also prevent your body from healing quickly from inflammatory skin conditions.
Diagnosing hives
To diagnose hives, your primary care provider or dermatologist will examine your skin and ask questions about your symptoms and any possible causes. If you develop repeated cases of hives you may want to use a notebook or phone app to keep a symptom diary to share with your doctor. Tracking your symptoms and possible triggers could help identify what’s causing your hives.
Your provider or dermatologist may also recommend allergy tests, blood work or a skin biopsy, according to the AAD.
Are hives contagious?
There's no evidence to suggest that hives are contagious, but whatever is causing the hives could be. In other words, if you break out in hives, you’re not going to infect anyone else with them, even if that person comes into contact with you. But if it’s an insect bite that caused your hives, someone else who gets bitten by that insect may also develop hives.
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.
An ice pack can alleviate the uncomfortable itching you get from hives. “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.”
And, while having hives is no fun, keep in mind that it's a temporary condition. If you're already feeling icky, you don't want to add in the extra stress of fixating on the hives.
This article was originally published on TODAY.com
