[{"@context":"https:\/\/schema.org\/","@type":"Article","@id":"https:\/\/share-dev.upmc.com\/2024\/08\/what-causes-hives\/#Article","mainEntityOfPage":"https:\/\/share-dev.upmc.com\/2024\/08\/what-causes-hives\/","headline":"What Causes Hives: When to Worry (Overview and Remedies)","name":"What Causes Hives: When to Worry (Overview and Remedies)","description":"

Learn about hives, their causes, symptoms, and treatments. Understand when to seek medical help and how to manage this common skin reaction.<\/p>","datePublished":"2024-08-09","dateModified":"2024-10-02","author":{"@type":"Organization","@id":"https:\/\/www.upmc.com\/","name":"UPMC","url":"https:\/\/www.upmc.com\/","sameAs":"https:\/\/share-dev.upmc.com\/upmc\/","parentOrganization":"UPMC"},"publisher":{"@type":"Organization","name":"UPMC HealthBeat","logo":{"@type":"ImageObject","@id":"https:\/\/share-dev.upmc.com\/wp-content\/uploads\/2019\/04\/UPMC-HealthBeat-Logo.png","url":"https:\/\/share-dev.upmc.com\/wp-content\/uploads\/2019\/04\/UPMC-HealthBeat-Logo.png","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/share-dev.upmc.com\/wp-content\/uploads\/2024\/07\/GettyImages-1483221343.jpg","url":"https:\/\/share-dev.upmc.com\/wp-content\/uploads\/2024\/07\/GettyImages-1483221343.jpg","height":865,"width":1999},"url":"https:\/\/share-dev.upmc.com\/2024\/08\/what-causes-hives\/","about":["Health Topics A-Z","Skin Care"],"wordCount":1220,"articleBody":"Chances are you or someone you know will develop urticaria, or hives, at some point. Some 20% of people get hives during their life, according to the American College of Allergy, Asthma & Immunology.Here\u2019s what you should know about hives and what to do about them.What Do Hives Look Like?Hives, also known as urticaria, are smooth bumps or raised welts with defined edges. Most are itchy. Itching can range from mild to severe. They can also vary in shape and size.Most people get hives in large, raised patches called plaques.Hive color depends on skin color:If you have dark-pigmented skin, your hives are often the same color or a bit lighter or darker.Your hives will look red or pink if you have light- or medium-pigmented skin.What is blanching?Blanching is a sign of hives. If you press on one, the center will turn white.How Long Do Hives Last?Hives can appear without warning. Millions of people develop hives without ever knowing why, according to the American Academy of Dermatology (AAD) Association.Most people develop hives for a few days to a few weeks. Most disappear within 24 hours. When they do, they rarely leave a mark.What is chronic spontaneous urticaria (CSU)?CSU is a medical condition also known as chronic hives.With CSU, someone develops hives for six weeks or longer without a known cause. Some people with CSU can have hives that appear for months or years.CSU may have some association with thyroid disease, hormonal problems, and, in rare cases, cancer. Women are twice as likely as men to get CSU, according to the AAD, often between the ages of 20 and 40.Where Can You Get Hives?You can get hives anywhere. They may also change shape or go away and come back. Most people get hives on:The abdomen or belly.The back.The buttocks.The chest.The upper arms or upper legs.Some also develop hives in their mucous membranes (the soft, moist tissue that lines your eyelids, mouth, and nose).When Should You Worry About Hives?Hives on their own aren’t a cause for concern. So, when should you worry about hives in adults and children?Hives can trigger angioedema \u2014 swelling of the tissue beneath your skin. Angioedema can cause your face, throat, hands, and feet to swell. Swelling in your throat can cause a life-threatening emergency.Other concerning symptoms include fever, joint pain, and eye issues. If you experience any of these with hives, seek immediate medical attention.What Causes Hives?Hives occur when your body releases histamine. Your immune system releases histamine and other chemicals in response to a threat, such as an infection. These can protect you from getting really sick.\u201cHives may be caused by a wide variety of triggers, which may include infection, medication, scratching on the skin, pressure on the skin, UV light, hot or cold air temperature changes, exercise, or sweating,” says Nathaniel Hare, MD. “They may also occur in the setting of a life-threatening allergic reaction known as anaphylaxis.”Allergic reactions Your body can release histamine in response to an allergic reaction. Common allergens that trigger hives include:Bite or sting from bees, mosquitoes, or spongy moth caterpillars.Foods such as eggs, peanuts, and shellfish.Latex.Medication, including antibiotics (especially penicillin and sulfamides\/sulfonamides).Pet dander.Plants, such as poison oak, ragweed, and stinging nettle.Pollen.Infections Some people get hives when they get infections, including:COVID-19.Hepatitis.Infectious mononucleosis, or mono.Strep throat.Urinary tract infections.Blood vessel inflammation, called vasculitis, can also cause hives.Medication Any medication may cause hives. According to the American Academy of Allergy, Asthma & Immunology, the most common include:Antibiotics, such as penicillin.Anticonvulsants.Aspirin and nonsteroidal anti-inflammatory medications, such as ibuprofen.Chemotherapy.Monoclonal antibody therapy.Medical treatmentsSome medical treatments can stress your skin. Medical treatments that can cause hives include:Blood transfusions.Radiation therapy.Other reasons\/inducible urticariaSometimes, your body may release histamine because of physical and environmental triggers. These can cause inducible urticaria. About 20% to 30% of people with CSU may have a form of inducible urticaria.Your body may release histamine in response to:Air temperature. Also called cold and heat urticaria.Anxiety or stress.Exercise, sweating, or hot showers. Also called cholinergic urticaria.Pressure on your skin, such as from tight or scratchy clothing. They’re also called pressure urticaria.Sunlight. Also called solar urticaria.Risk Factors for Hives: Are You at Risk?Anyone can get hives at any age. Hives are common during childhood. Some people may have a higher risk of developing hives, including:People with atopic dermatitis or eczema.People who smoke cigarettes.Women of African American heritage. They’re four to five times more likely to develop hives than white people.How to Get Rid of HivesManaging hives starts with avoiding your triggers. Your doctor may recommend taking allergen tests to find out your triggers.At-home treatmentsAt-home treatments help to manage your symptoms and get rid of hives. They include:AntihistaminesThese medications work to block a histamine reaction. Doctors consider antihistamines a first-line treatment for hives.Your doctor may recommend more than one. Newer antihistamines are nonsedating and don\u2019t make you drowsy. Older antihistamines are sedating and can make you drowsy.Nonsedating antihistamines include:Cetirizine (Zyrtec).Desloratadine (Clarinex).Fexofenadine (Allegra).Levocetirizine (Xyzal).Loratadine (Claritin).Sedating antihistamines include:Diphenhydramine (Benadryl).Hydroxyzine (Atarax).Anti-itch topicalsLotions containing hydrocortisone can reduce itching.Cold compressesApplying cold packs may help ease symptoms.Prescription treatments for hivesYou may need prescription medication to treat your hives. These include:CorticosteroidsThese include prednisone or prednisolone. You can\u2019t take them long-term. But they may help relieve severe symptoms for a few days.Epinephrine auto-injectorIf your lips, tongue, or throat swell, your doctor may prescribe this medication, also called an EpiPen, to keep with you at all times. It can prevent anaphylaxis, a potentially fatal allergic reaction that can cause trouble breathing and send your body into shock.Omalizumab (Xolair)This is an FDA-approved treatment for CSU or chronic hives. This medication comes in the form of a monthly injection under the skin.When Should I Call a Doctor for Hives?You should see your doctor or a dermatologist if you have widespread hives or hives for more than six weeks. They can help make sure that what you have are hives. They can also come up with a treatment plan.When Are Hives an Emergency?Hives can turn severe and life-threatening if you have:Difficulty breathing.Lightheadedness.Nausea, vomiting, or diarrhea.Swelling in your mouth, lips, or throat.These are often signs of anaphylaxis. If you have these symptoms, use your EpiPen and call 911 or have someone take you to the nearest emergency room.You should also get emergency care if you have:Eye pain.Fever.Joint pain.Editor's Note: This article was originally published on August 9, 2024, and was last reviewed on October 2, 2024.SourcesAmerican Academy of Dermatology Association. Hives: FAQs. LinkAmerican Academy of Dermatology Association. Hives: Signs and Symptoms. LinkAmerican Academy of Allergy, Asthma, & Immunology. Hives: Overview. LinkAmerican Academy of Allergy, Asthma & Immunology. Allergic Skin Conditions. LinkThe Journal of Allergy and Clinical Immunology. How to Approach Chronic Inducible Urticaria. LinkAmerican Academy of Allergy, Asthma & Immunology. Medications and Drug Allergic Reactions. 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