Hives are an itchy, red, and irritated skin reaction that can often look worse than they feel, although sometimes the opposite is true. You can usually divide the causes into two categories: allergic reactions and environmental triggers.

Once you know the cause of the hives on your stomach, you can find treatments that may help reduce discomfort and avoid potential triggers in the future.

Keep reading to find out why you or a loved one may experience hives on your stomach.

Doctors know there are some common underlying causes of hives. Unfortunately, sometimes, especially with chronic hives, your doctor won’t be able to identify why you’re experiencing these itchy bumps.

1. Allergic reactions

Allergic reactions to foods or medications can lead to hives on the stomach as well as other areas of the body. Typically, if the reaction is to something you ate or a new medication, it will happen pretty quickly.

However, there are some exceptions where you can have a delayed reaction as the body absorbs more of the food or medicine. You may also notice swelling at areas where the food or medicine has touched, such as on your lips. You may also experience problems swallowing.

2. Chronic hives

Chronic hives often have no known cause. Doctors often think they are the result of an autoimmune disorder, where the body attacks healthy cells as if they are foreign invaders, such as bacteria or viruses.

3. Heat or cold exposure

Heat and sweating or exposure to ice or very cold temperatures on the stomach can lead to hives. Maintaining the skin at a more constant, regular temperature can help whenever possible. Because babies can’t regulate their body temperatures as well as adults, they may be especially vulnerable to temperature extremes.

4. Insect bites or stings

Insect bites and stings can cause hive reactions that may occur at the site of the bite or may seem to transmit to other places on the body. Because little ones have less surface area than adults, and often more sensitive skin, the hives may appear more pronounced.

5. Stress

The mind-body connection is real. Extreme stress can cause you to experience hives on the stomach. Your skin may start to feel hot and itchy. And when you scratch it, guess what? The hives get worse.

The American Institute of Stress reports that women in their 30s and 40s report stress hives in the greatest amounts — but they can really affect anyone at any age. They’ll usually go away in about 24 hours.

6. Scratching or rubbing the skin

Doctors call these kind of hives dermatagraphic urticaria. The friction against the skin can irritate the skin and cause swellings and hives. Sometimes, you may itch or rub your skin when your skin is very dry. Keeping it moisturized can help.

7. Too much sun

Also known as solar urticaria, excess sun can set off an inflammatory reaction that causes hives on the stomach. Because the stomach often doesn’t get as much sun as other areas of skin, it can be an especially vulnerable spot for hives.

The definition of excess sun exposure can vary. For very fair individuals, even a few minutes of sun exposure may be too much.

8. Too-tight clothing

Pressure and friction on the skin can lead to irritation that causes hives. This is especially true on the stomach if you have on a too-tight waistband.

The good news is that you can usually relieve the problem pretty quickly by putting on some looser clothing. This can help you breathe easier and minimize irritation.

9. Vibrations

Although a rare cause of hives, it is possible that a person can experience hives related to vibration. This could be due to vibrations from holding a tool, a massager, or even from riding in a car.

10. Viral infections

Viruses can cause rashes that commonly lead to hives. This is especially true in infants and young people, who may be more prone to viral rashes.

Examples of pediatric viral illnesses that can cause rashes on the stomach include: fifth disease, measles, and hand, foot, and mouth disease. These hives may or may not be itchy to a little one.

Hives can take on several different appearances, which can make them tricky to recognize. There is one thing in common — they usually are red compared to the rest of the skin.

Some of the other appearances for hives include:

  • Sponge-like appearance: Histamine released due to allergic reactions can cause blood vessels near the top of the skin to leak fluid. This can cause swelling and a “sponge-like” appearance to the skin.
  • Flat: While some hives are spongy or raised, others are flat on the skin. Flat gives may appear in large patches that aren’t any particular shape.
  • Overlapping: Hives often look like circles that are laid over each other. Doctors describe this as “polycircular” in appearance.

Chronic hives

Chronic hives are those that last longer than six weeks. They usually appear a little differently than acute hives, which usually have a known cause such as allergic reactions, heat, or viral infection.

Chronic hives usually look like flat, red areas that appear as if someone has scratched the skin.

Sometimes it’s hard to tell hives from a rash or other skin issue on the stomach. Here are some pictures that may help you quickly tell the difference.

Treatments for hives on the stomach really depend on the underlying cause and if the hives are affecting other areas of your body, like your throat and airways.

Emergency cases

In extreme cases of hives that also involve trouble breathing and swallowing, you’ll need emergency medical attention.

  • If you have an injectable epinephrine pen, now’s the time to use it.
  • If you don’t, call 911 or have a loved one call 911 immediately.
  • A doctor may administer intravenous epinephrine as well as antihistamines like diphenhydramine (Benadryl).
  • You may also need steroids if the hives are really severe.
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Non-emergency cases

If you aren’t having trouble breathing, aren’t extremely nauseated, or not in pain due to your hives, you can treat them at home with these measures:

  • Take an over-the-counter antihistamine, such as diphenhydramine (Benadryl), fexofenadine (Allegra) or loratadine (Claritin). Benadryl is more likely to cause drowsiness than the other two options.
  • Apply cool compresses using soft washcloths or other cloths to the stomach. Some people will soak the washcloths in whole milk. Skim milk doesn’t have the same fat level which means it isn’t as soothing.
  • Apply topical steroids, such as hydrocortisone. This may reduce itching and irritation.

If you experience chronic hives, a doctor may prescribe the medication omalizumab. This medication helps those who have hives, yet don’t respond to antihistamines. An estimated 65 percent of people with chronic hives will respond to this medication.

You should seek immediate medical attention if you are experiencing hives on your stomach along with signs of anaphylaxis. These symptoms include:

  • dizziness
  • lip, tongue, and eye swelling
  • problems breathing

You need immediate care if you are experiencing an anaphylaxis episode. Don’t delay in calling 911 or having a loved one call 911.

There are other, non-emergency situations when you should also see your doctor. These include when you experience hives on your stomach on a regular basis, or they’re interfering with you sleep or daily activities.

Hives can be irritating, but are not, for the most part, limiting. After about 24 hours, they’ll go away. If you have chronic hives or severe allergic reactions, treatments may have to be more intensive.