What are hives?
This is a skin reaction that causes bumps, raised patches, or both to suddenly appear on the skin. The bumps and raised patches are often itchy and may look swollen. The medical name for hives is urticaria.
Are hives contagious?
No, you cannot get hives by touching someone else’s hives or being around someone who has hives.
However, some people develop hives when they have a contagious disease like strep throat or a common cold. If someone with hives has a contagious disease, you can catch the contagious disease — but not hives.
Most hives are intensely itchy. The size of an individual hive ranges from as small as a pinhead to several inches across. Hives can appear alone or in a group. Some hives join together to form large patches called plaques.
Hives come in different shapes and sizes
This patient developed welts that look like small bumps and large patches.
Swelling can be a medical emergency
Along with hives, some people develop swelling deep in their skin or the moist tissue that lines the mouth/lip, eyelids, or other areas. This swelling is called angioedema.
Angioedema is usually harmless; however, it becomes a life-threatening emergency if it causes:
Angioedema can also cause noticeable swelling on the lips, eyes, and other parts of the body. It usually goes away in a few days. Until the swelling subsides, you may feel uncomfortable.
If swelling develops in your mouth or throat or you have or difficulty breathing, get immediate medical care or go to the nearest emergency room.
How long do hives last?
Hives are usually harmless and temporary. A single hive tends to last for a few minutes to a few hours. Most hives clear within 24 hours.
As existing hives clear, new ones can form. New hives may appear on the same or different areas on the skin. Most people get new hives for a few days to a few weeks.
If new hives continue to appear for six weeks or longer, you have a condition called chronic hives.
When the cause of chronic hives is unknown, the condition is called chronic spontaneous urticaria (CSU). People who have CSU get new hives daily — or almost daily. This can continue for months or years.
Living with CSU can affect your quality of life. Some people say they feel a loss of control because they never know when hives will appear. Though, hives often worsen during the night. This can make it difficult to sleep.
A continual loss of sleep can make you feel tired and irritable. Some people develop anxiety or depression. All of this can affect your ability to do well in school or at work.
Dermatologists care for people who have chronic hives. Treatment can help relieve the discomfort. If a cause can be found, avoiding the cause can prevent new hives.
For some people, the cause of their hives is something that touches their skin. Your own sweat, cold, sunlight, or the light pressure of a purse strap can cause hives. Dermatologists call this type of hives inducible hives. It only develops when something that causes hives for that person touches the skin.
When this type of hives continues for six weeks or longer, it’s called chronic inducible hives. By avoiding the cause, you can prevent new hives.
Just as hives have many causes, they can also appear on the skin in many ways. You’ll find pictures that show what hives can look like at: Hives: Signs and symptoms.
Related AAD resources
Image
Used with permission of DermNet NZ.
References
Antia C, Baquerizo K, et al. “Urticaria: A comprehensive review: Epidemiology, diagnosis, and work-up.” J Am Acad Dermatol. 2018;79(4):599-614.
Grattan CEH and Saini SS. “Urticaria and angioedema.” In: Bolognia JL, et al. Dermatology. (4th edition). Mosby Elsevier, China, 2018:304-19.
Hide M, Takahagi S, et al. “Urticaria and angioedema.” In: Kang S, et al. Fitzpatrick’s Dermatology. (9th edition) McGraw Hill Education, United States of America, 2019:684-785.
Rosman Y, Hershko AY, et al. “Characterization of chronic urticaria and associated conditions in a large population of adolescents.” J Am Acad Dermatol. 2019;81(1):129-135.
Silvestre Salvador JF, Giménez-Arnau AM, et al. “Managing urticaria in the emergency department: Recommendations of a multidisciplinary expert panel.” Emergencias. 2021 Aug;33(4):299-308.
Wertenteil S, Strunk A, et al. “Prevalence estimates for chronic urticaria in the United States: A sex- and age-adjusted population analysis.” J Am Acad Dermatol. 2019;81(1):152-6.
Wong HK. “Urticaria.” In: Medscape (Elston DM., Ed.) Last updated 9/16/2020. Last accessed 8/1/2021.
Yosipovitch G and Kwatra SG. “Chronic urticaria.” In: Living with itch: A patient’s guide. The Johns Hopkins University Press. United States, 2013: 56-9.
Written by:
Paula Ludmann, MS
Reviewed by:
Rajiv Nijhawan, MD, FAAD
Dara Spearman, MD, FAAD
Last updated: 9/28/21
All content solely developed by the American Academy of Dermatology
Hives: Signs and symptoms
If swelling develops in your mouth or throat or you have or difficulty breathing, get immediate medical care or go to the nearest emergency room.
Where do hives develop on the body?
Hives can develop anywhere on your skin. For most people, hives appear on one or more of these areas:
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Abdomen
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Back
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Buttocks
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Chest
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Upper arms
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Upper legs
If you have hives, they may appear in one area like your back or cover much of your skin.
Hives can also develop on soft, moist tissue that lines your eyelids, mouth, and other areas. The medical name for this moist tissue is mucous membrane.
Some people always get hives in the same place (or places) on their body
This usually happens when something triggers hives like medication, stress, or sunlight.
When hives develop in the same place every time, this is called fixed hives.
What are the signs and symptoms of hives?
Hives cause raised, visible, and often itchy welts on the skin, mucous membranes (described above), or both.
Hives can develop at any age
It is a common disease in children.
What do hives look like on the skin?
These itchy welts can appear on the skin in many ways, as the following pictures of hives show.
Hives develop in batches
Hives appear suddenly, causing a rash of smooth, raised welts that tend to differ in size and shape. The welts can be small, large, or somewhere in between. Some hives are as big as a hand.
The color of hives varies with skin color
If you have brown or black skin, hives are often the same color as your skin, or slightly darker or lighter than your natural skin color. People who have a light or medium complexion see red or pink hives.
Individual hives come and go quickly, usually within 24 hours
As some hives disappear, new hives may form. Most people have a case of hives for a few days to a few weeks. If new hives continue to appear for more than 6 weeks, you have a condition called chronic hives.
Skin itches, burns, or stings and feels warm to the touch
Hives can itch, sometimes intensely. Some people say that hives burn or sting rather than itch. Because the skin is inflamed, hives often feel warm to the touch.
Hives can cover large areas of skin
Some people get hives in a few places. It’s also possible for hives to cover a large portion of the body, which can feel uncomfortable because hives tend to itch.
A telltale sign of hives is blanching
This means that if you have a light or medium skin color, pressing on a hive will cause the red or pink color to disappear while you’re pressing on it.
Hives usually appear as distinct raised spots or patches
Sometimes, hives run together, as shown here. The large, raised patches are called plaques.
Some people also develop swelling deep in their skin
Hives cause inflammation in the skin, so the skin may feel hot and swollen. Some people who get hives also develop another type of swelling that occurs deep in the skin or moist tissue that lines the lips, mouth, inside of the eyelids, and elsewhere.
This swelling is called angioedema. It tends to cause pain rather than itch.
Swelling (angioedema) on the lower lip
Angioedema causes pain rather than itch and is more noticeable than the swelling caused by hives. Angioedema usually lasts for 2 to 3 days. If angioedema develops in your mouth or throat, get immediate medical care because the swelling can make breathing difficult.
While hives are common, some people are more likely than others to develop them. Find out if you have a higher risk at: Hives: Causes.
Related AAD resources
Images
Image 1: Used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.
Images 2-10: Used with permission of DermNet NZ.
References
Grattan CEH and Saini SS. “Urticaria and angioedema.” In: Bolognia JL, et al. Dermatology. (4th edition). Mosby Elsevier, China, 2018:304-19.
Hide M, Takahagi S, et al. “Urticaria and angioedema.” In: Kang S, et al. Fitzpatrick’s Dermatology. (9th edition) McGraw Hill Education, United States of America, 2019:684-785.
Yosipovitch G and Kwatra SG. “Chronic urticaria.” In: Living with itch: A patient’s guide. The Johns Hopkins University Press. United States, 2013: 56-9.
Written by:
Paula Ludmann, MS
Reviewed by:
Rajiv Nijhawan, MD, FAAD
Dara Spearman, MD, FAAD
Last updated: 9/28/21
All content solely developed by the American Academy of Dermatology
Hives: Causes
What causes hives?
Hives are often-itchy bumps and raised patches that develop when the body releases histamine.
Your body stores histamine inside cells. When your immune system recognizes a threat, it releases histamine and other chemicals. This cascade of chemicals can protect you from becoming seriously ill from an infection, spoiled fish, or a bug bite.
Sometimes, the immune system releases histamine when there is no real threat. This happens when people develop an allergic reaction. In fact, some people develop hives when they have an allergic reaction.
Some people develop hives when they have an allergic reaction
The hives on this boy’s skin are due to an allergic reaction to mosquito bites.
When the body mistakenly releases histamine and hives develop, the cause is often one of the following:
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An allergic reaction
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Overreaction to heat, sweat, or cold
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Stress
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Sunlight
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Pressure on the skin (tight clothing, light touch of a purse strap, or scratching)
When hives are due to an allergic reaction, it’s often an allergy to:
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A food
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Bug bite or sting
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Latex
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Medication
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Pet dander
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Plant
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Pollen
Infection or medical treatment can trigger hives
Some people get hives when they develop an infection like strep throat, a urinary tract infection, or COVID-19.
Others get hives when they have a medical treatment like radiation therapy or a blood transfusion.
Hives was the first sign of COVID-19 for this girl
A few days after getting hives, this 5-year-old girl began to develop the more common symptoms of COVID-19 like fever and a cough.
Hives due to radiation therapy
This medical treatment can be lifesaving but hard on your skin. If your body releases histamine to protect itself, hives can develop.
What triggers hives often remains a mystery
While some people can trace hives back to a trigger like an allergic reaction, exposure to cold, or stress, the cause remains a mystery for many people.
It’s estimated that millions of people in the United States will develop hives during their lifetime and never find the cause. Some of these people will continue to have hives for six weeks or longer. When this happens, the person has a medical condition called chronic spontaneous urticaria (CSU).
Urticaria is the medical word for hives.
With CSU, hives can continue to appear for months and sometimes years. During this time, the swelling, pain, and discomfort can be difficult to live with.
Women are twice as likely as men to develop CSU during their lifetime. Most women develop CSU when they are 20 to 40 years of age.
Some people have greater risk of developing any type of hives
While anyone can develop hives, you have a greater risk if you:
If you have long-lasting or widespread hives, seeing a dermatologist can help you feel more comfortable. Seeing a dermatologist is also a good idea to make sure that what you have really is hives.
Find out how dermatologists diagnose and treat hives at: Hives: Diagnosis and treatment.
Related AAD resources
Images
Image 1: Used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.
Image 2: Images used with permission of JAAD Case Reports.
Image 3. Image used with permission of the Journal of the American Academy of Dermatology.
References
Antia C, Baquerizo K, et al. “Urticaria: A comprehensive review: Epidemiology, diagnosis, and work-up.” J Am Acad Dermatol. 2018;79(4):599-614.
Grattan CEH, Saini SS. “Urticaria and angioedema.” In: Bolognia JL, et al. Dermatology. (4th edition). Mosby Elsevier, China, 2018:304-19.
Hide M, Takahagi S, et al. “Urticaria and angioedema.” In: Kang S, et al. Fitzpatrick’s Dermatology. (9th edition) McGraw Hill Education, United States of America, 2019:684-785.
Hymes SR, Strom EA, et al. “Radiation dermatitis: Clinical presentation, pathophysiology, and treatment.” 2006. J Am Acad Dermatol. 2006;54(1):28-46.
Le NK, Brooks JP. “Acute urticaria as the initial presentation of COVID-19 in a pediatric patient.” JAAD Case Rep. 2021;11:137-8.
Rosman Y, Hershko AY, et al. “Characterization of chronic urticaria and associated conditions in a large population of adolescents.” J Am Acad Dermatol. 2019;81(1):129-135.
Written by:
Paula Ludmann, MS
Reviewed by:
Rajiv Nijhawan, MD, FAAD
Dara Spearman, MD, FAAD
Last updated: 9/28/21
All content solely developed by the American Academy of Dermatology
Hives: Diagnosis and treatment
If you have a mild case of hives, it will likely go away in a few days. To get relief until then, dermatologists recommend that you take a non-drowsy antihistamine and use these home remedies.
It can be helpful to see a board-certified dermatologist if the hives:
Hives can require emergency care
Get immediate medical care or go to the nearest emergency room if you have hives, along with any of the following:
- Problem swallowing
- Feel light-headed or faint
- Swelling in your mouth or throat
- Racing heart
You may have anaphylaxis, which can be deadly and requires immediate medical care.
How do dermatologists diagnose hives?
A dermatologist can often diagnose hives by looking at your skin.
To find out why you have hives, your dermatologist will ask questions. Knowing why you have hives may help you avoid the cause, which can prevent new hives.
Hives have many causes, so it can be a challenge to find the cause. You can help your dermatologist by taking time to answer these questions before your appointment:
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How often do you get hives?
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How long do the hives last?
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Do the hives itch or feel painful?
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When you get hives, do you have other symptoms like feeling lightheaded or nauseous?
It can also be helpful to think about what you were doing a few hours before you developed hives. For example, can you answer the following questions?
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What did you eat?
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Did you take a medication, including one that you can buy without a prescription, such as ibuprofen?
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Have you been feeling stressed?
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Did a bug bite or sting you?
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Were you out in sunlight, cold, or heat?
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Did you sweat a lot?
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Were you wearing tight clothes or carrying a purse or backpack?
Tell your dermatologist if you develop hives hours after eating red meat (e.g., beef, pork, or organ meat), gelatin, or dairy products
Hives can be a sign of alpha-gal syndrome, a food allergy that can develop after being bite by the lone star tick. This tick is found in many U.S. states.
During your appointment, your dermatologist will also ask about your medical history. Be sure to mention any recent medical treatments, including radiation therapy or a blood transfusion.
Your dermatologist may also require one or more of the following medical tests:
To perform a skin biopsy, your dermatologist removes a small bit of affected skin so that it can be examined under a microscope.
While having answers to these questions and test results is helpful, it’s important to know that the cause of hives cannot always be found.
If a cause cannot be found and you’ve had hives for 6 weeks or longer, the medical term for this is chronic spontaneous urticaria (CSU). Many people have CSU.
Even without knowing the cause, your dermatologist can treat hives.
How do dermatologists treat hives?
When treating hives, the goals are to:
Your treatment plan will be tailored to your needs and may include one or more of the following:
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Soothing anti-itch lotion or cream: Prax lotion or a cream containing menthol can give you temporary relief from the itch.
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An antihistamine: This medication can help control the itch and swelling. You can buy some antihistamines like cetirizine (Zyrtec®), loratadine (Claritin®), and Benadryl® without a prescription. Benadryl can make you sleepy, so it’s best taken at bedtime. If you need a stronger antihistamine, your dermatologist may prescribe doxepin.
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Corticosteroid: When hives are severe, a medication like prednisone can reduce the inflammation and itch. For milder hives, your dermatologist may prescribe a corticosteroid that you apply to your skin to help relieve the itch.
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Omalizumab: This is an injectable medication that you would use at home to treat chronic hives. It’s prescribed when antihistamines fail to work.
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Auto-injector: Also known as the EpiPen®, this medication treats a life-threatening allergic reaction.
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Light therapy: Also called phototherapy, this non-invasive treatment can be effective when antihistamines don’t work. It requires several trips a week for a few months to your dermatologist or phototherapy treatment center.
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Other medication as needed: Sometimes, hives can be a challenge to treat. If antihistamines and other treatments fail to work, your dermatologist will consider your unique needs and may prescribe another medication like cyclosporine or hydroxychloroquine. These medications work to calm down the immune system so that it doesn’t overreact.
To improve your outcome, your dermatologist may give you self-care tips to follow. To see what dermatologists frequently recommend, go to: Hives: Self-care.
Related AAD resources
Images
Image 1: Used with permission of DermNet NZ
Image 2: Getty Images
References
Antia C, Baquerizo K, et al. “Urticaria: A comprehensive review: Epidemiology, diagnosis, and work-up.” J Am Acad Dermatol. 2018;79(4):599-614.
Antia C, Baquerizo K, et al. “Urticaria: A comprehensive review: Treatment of chronic urticaria, special populations, and disease outcomes.” J Am Acad Dermatol. 2018;79(4):617-33.
Grattan CEH, Saini SS. “Urticaria and angioedema.” In: Bolognia JL, et al. Dermatology. (4th edition). Mosby Elsevier, China, 2018:304-19.
Hide M, Takahagi S, et al. “Urticaria and angioedema.” In: Kang S, et al. Fitzpatrick’s Dermatology. (9th edition) McGraw Hill Education, United States of America, 2019:684-785.
Wong HK. “Urticaria.” In: Medscape (Elston DM., Ed.) Last updated 9/16/2020. Last accessed 8/1/2021.
Yosipovitch G and Kwatra SG. “Chronic urticaria.” In: Living with itch: A patient’s guide. The Johns Hopkins University Press. United States, 2013: 56-9.
Written by:
Paula Ludmann, MS
Reviewed by:
Rajiv Nijhawan, MD, FAAD
Dara Spearman, MD, FAAD
Last updated: 9/28/21
All content solely developed by the American Academy of Dermatology
Hives: Self-care
How to treat hives in children
Has your child broken out in an itchy rash? If so, it could be a case of hives. Fortunately, hives are usually harmless and temporary. If your child has hives, follow these tips from dermatologists to help care for your child at home.
Most hives go away on their own in a few days or weeks. During this time, you can often relieve the itch and discomfort at home with these tips from board-certified dermatologists.
If you’re seeing a dermatologist for treatment, these tips can also be help reduce your discomfort.
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Try not to scratch: This can be difficult as hives are notoriously itchy. When you stop scratching, you stop irritating your skin.
If you have brown or black skin, not scratching also helps to reduce your risk of developing dark areas on your skin, which can appear after the hives clear, and often last much longer than the hives themselves.
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Ease the itch: When your skin starts to itch, any of the following can bring relief:
- Apply a cool compress to your itchy skin. To make a cool compress, run a clean washcloth under cold water to get it wet. Wring out the washcloth so that the water doesn’t drip. Then place the wet, cool washcloth on the itchy skin. Leave the washcloth on the itchy area for 10 to 20 minutes.
- Spread an anti-itch cream (or lotion) on the itchy skin. Be sure to follow the directions. If your dermatologist has prescribed one, be sure to use it.
- Add colloidal oatmeal to a bathtub of lukewarm water and soak for the time recommended on the package.
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Wear loose-fitting, 100% cotton clothes: This can reduce the irritation on your skin.
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Use lukewarm water when taking a bath or shower: When bathing, you want to be very gentle with your skin. Avoid rubbing the itchy skin with a washcloth, loofah, or mesh sponge. It’s best to apply your soap or cleanser by gently putting it on your skin with your hands.
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Wash with a gentle, fragrance-free soap or cleanser: Make sure that you use a fragrance-free product rather than an unscented one. An unscented product contains fragrance that’s been covered up so that you cannot smell it. Because an unscented product contains fragrance, it can still irritate your skin.
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If you have long-lasting hives or you get hives frequently, keep a journal: Hives develop for many reasons, so it can be difficult to figure out what’s causing them. Keeping a journal may help you find the cause. If you can avoid what’s causing the hives, you can prevent new hives.
You want to jot down the following:
- Date and time the hives started
- What you were doing before the hives began
- Foods and drinks you recently had
- Medications you recently took, including aspirin, ibuprofen, and any prescription medications
- If you recently felt overheated or sweat heavily
- What you were wearing and carrying
- If you’ve been feeling stressed
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Keep learning about hives: If you’ve had hives for six weeks or longer, you have a condition called chronic hives. Learning more about hives can help you manage this challenging condition. You’ll find more information about chronic hives at:
Written by:
Paula Ludmann, MS
Reviewed by:
Rajiv Nijhawan, MD, FAAD
Dara Spearman, MD, FAAD
Last updated: 9/28/21
All content solely developed by the American Academy of Dermatology
