Why do I suddenly get hives
What to Know If Youre Breaking Out in Hives for No Apparent Reason
If your skin is breaking out in hives, it may be a sign of an underlying health condition like lupus or infection. It could also be an allergic reaction. Speaking to an allergist can help with diagnosis and treatment.
Sometimes the source of the raised, red, and itchy bumps on your skin can be a mystery.
One reason hives can be so surprising is that they can be caused by many things you might not expect including stress and exercise. Most of these unexpected causes for hives arent serious, but some are a sign its a good idea to make a medical appointment.
Read on for more information about reasons you may have hives.
Hives are an itchy reaction on your skin. They happen when a chemical called histamine is released in your body.
They can appear anywhere on your body and can be tiny pinprick-sized bumps or large raised areas that cover an entire limb. Hives often appear red or pink on white or light skin. People with darker skin might have hives that are slightly lighter or slightly darker than the skin surrounding them.
No matter the color of your hives rash, all hives share these qualities:
- raised
- itchy
- tender
- round, oval, or uneven shaped
- clearly defined border
Hives are also called urticaria. Sometimes, the cause of hives is obvious. For instance, you might have an immediate reaction to something youre allergic to such as pollen or pet dander. However, the cause isnt always clear. Hives can be sudden and surprising and seem to not have a cause.
Hives are a very common skin reaction that can come from some unexpected sources. Some causes you might not have thought of include:
- Colds and other viral infections. Sometimes hives can be caused by your immune system fighting colds and other viral infections. These hives often appear near the end of your cold or virus as youre starting to feel better. Theyre most common in children but can happen to anyone.
- Bacterial infections. Bacterial infections such as strep throat or urinary tract infections can also sometimes trigger hives as your body reacts to the bacteria. These hives will fade as the antibiotics help your body fight the infection. They might peel before healing completely.
- Chronic conditions such as lupus. Hives that last for longer than 6 weeks might be a sign of an autoimmune condition such as lupus, type 1 diabetes, thyroid disease, or rheumatoid arthritis. These hives wont go away on their own. Its a good idea to make a medical appointment to get this type of hive checked out and see if a chronic condition is the cause.
- Stress. Stress can raise your internal body temperature and release adrenalin and other chemicals that might trigger hives. Stress hives tend to be located on the face, neck, chest, and arms. Theyre common in people with eczema, allergies, or sensitive skin.
- Temperature changes. Suddenly encountering hot or cold, such as stepping into a steamy shower or entering a swimming pool, can cause histamine to release and hives to form. Hives that form in response to temperature are called cold urticaria. A red and itchy area of skin often forms around these hives.
- Tight clothing. Tight clothing can cause friction that leads to irritation and to hives. Clothes that sit close to your skin can also push any bacteria on your skin surface into your pores and hair follicles.
- Exercise. A chemical called acetylcholine is released in your body when you exercise can affect your skin cells and cause irritation and hives. Exercise hives are known as exercise-induced urticaria. Some people have additional symptoms along with hives such as shortness of breath, headache, flushing, and stomach cramps.
- Inflammation of blood vessels. An inflammation of your blood vessels known as vasculitis can cause painful hives. They can leave a bruise on your skin and last for several days. Vasculitis is a serious medical condition that requires treatment by a medical professional.
- Medications. Some medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, and opioids can cause an allergic reaction that leads to hives. Hives following medication might be the first sign of a medical emergency called anaphylaxis. Other symptoms of anaphylaxis include shortness of breath, wheezing, vomiting, and loss of consciousness.
Hives are often caused by identifiable allergies. Avoiding these allergens can help you avoid breaking out in hives. Common hive triggers include:
Hives can be a sign of a serious allergic reaction that needs emergency medical emergency attention. Its important to take action if you hives along with any of these symptoms:
- wheezing
- tightness in your chest or throat
- trouble breathing
- trouble talking
- swelling in your throat, face, or tongue
- nausea
- lightheadedness
If you are experiencing any of these symptoms, call 911.
A doctor may prescribe you an epinephrine injector, such as an EpiPen, for future allergic reactions. Theyll teach you how to use it and answer any questions you might have. Youll keep your epinephrine injector on hand and use it if you develop hives in the future.
Youll still need to visit the emergency room after you use your epinephrine injector, but it can stop anaphylaxis from becoming deadly.
A doctor can diagnose hives and help you find the cause. They might recommend you keep a food diary to find out if there is any link between food and your hives.
You might be sent to an allergist, a doctor who specializes in treating allergies, for additional testing. This might include blood work and urine tests to look for chemicals in your body that might tell the allergists whats causing your hives.
You might also have a skin biopsy, especially if your allergist suspects vasculitis causing your hives. Hives that have lasted for longer than 6 weeks will likely necessitate testing for underlying chronic conditions.
Sometimes, a specific cause isnt found. In this case, your hives will be diagnosed as idiopathic urticaria. The word idiopathic means unknown. In this case, your doctor will still be able to help you with a treatment plan, but you wont be able to tell what to avoid to prevent hives in the future.
Treatment for hives will depend on the severity of your hives and on the cause. For instance, youll need to avoid the cause of your hives if it has been found.
Your doctor will work with you to find the right treatment for you. Common options include:
- Antihistamines. Both over-the-counter and prescription antihistamines block histamine and can treat hives. You might find that certain antihistamines are more effective for you than others. Sometimes a combination of antihistamines is recommended.
- Anti-itch lotions. Lotions to calm down itching and redness can provide relief from hives and prevent scratching.
- Antibiotics. Hives that are linked to bacterial infections can be treated with antibiotics
- Corticosteroids. Corticosteroids can be taken on a short-term basis to help with severe cases of hives.
Read more about hives treatment options.
Hives can sometimes be surprising and have no obvious cause. There are actually a wide variety of things that can cause hives, including stress, colds, exercise, and temperature changes. Chronic hives can point to an underlying condition such as lupus.
An allergist can help you determine the cause of your hives and start treatment.
Hives and angioedema
Overview
Hives
Hives
Illustration of hives on different skin colors. Hives can cause swollen, itchy welts. Hives is also called urticaria.
Angioedema
Angioedema
Illustration of angioedema on different skin colors. Angioedema causes swelling in the deeper layers of skin, often of the face and lips. It often goes away within a day.
Hives also known as urticaria (ur-tih-KAR-e-uh) is a skin reaction that causes itchy welts that range in size from small spots to large blotches. Hives can be triggered by many situations and substances, including certain foods and medications.
Angioedema can arise with hives or alone. It causes swelling in the deeper layers of skin, often around the face and lips. Short-lived (acute) hives and angioedema are common. Most times, they are harmless, clear up within in a day and don't leave any lasting marks, even without treatment. Hives that last longer than six weeks are called chronic hives.
Hives and angioedema are usually treated with antihistamine medication. Angioedema can be life-threatening if swelling of the tongue or in the throat blocks the airway.
Symptoms
Hives
The welts associated with hives can be:
- Skin-colored, reddish on white skin, or purplish on black and brown skin
- Itchy, ranging from mild to intense
- Round, oval or worm-shaped
- As small as a pea or as large as a dinner plate
Most hives appear quickly and go away within 24 hours. This is known as acute hives. Chronic hives can last for months or years.
Angioedema
Angioedema is a reaction similar to hives that affects deeper layers of the skin. It can appear with hives or alone. Signs and symptoms include:
- Welts that form in minutes to hours
- Swelling, especially around the eyes, cheeks or lips
- Mild pain and warmth in the affected areas
When to see a doctor
You can usually treat mild cases of hives or angioedema at home. See your health care provider if your symptoms continue for more than a few days.
If you think your hives or angioedema was caused by a known allergy to food or a medication, your symptoms may be an early sign of an anaphylactic reaction. Seek emergency care if you feel your tongue, lips, mouth or throat swelling or if you're having trouble breathing.
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Causes
For most people who experience acute hives and angioedema, the exact cause can't be identified. The conditions are sometimes caused by:
- Foods. Many foods can trigger reactions in people with sensitivities. Shellfish, fish, peanuts, tree nuts, soy, eggs and milk are frequent offenders.
- Medications. Many medications may cause hives or angioedema, including penicillins, aspirin, ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve) and blood pressure medications.
- Airborne allergens. Pollen and other allergens that you breathe in can trigger hives, sometimes accompanied by upper and lower respiratory tract symptoms.
- Insect bites and infections. Other causes of acute hives and angioedema are insect bites and infections.
Risk factors
Hives and angioedema are common. You may be at increased risk of hives and angioedema if you:
- Have had hives or angioedema before
- Have had other allergic reactions
- Have a family history of hives, angioedema or hereditary angioedema
Complications
Severe angioedema can be life-threatening if swelling of the tongue or in the throat blocks the airway.
Prevention
To lower your likelihood of experiencing hives or angioedema, take the following precautions:
- Avoid known triggers. If you know what has triggered your hives, try to avoid that substance.
- Bathe and change your clothes. If pollen or animal contact has triggered your hives in the past, take a bath or shower and change your clothes if you're exposed to pollen or animals.
Oct. 27, 2023
Hives: Pictures, Causes, and How to Treat Them
Hives typically occur as an allergic response to something in your environment or something you ate. But they may sometimes happen because of an underlying health issue.
Hives, also known as urticaria, are itchy, raised welts that are found on the skin. Theyre usually red, pink, or flesh colored on lighter skin and may be flesh colored or slightly lighter or darker than your skin tone on brown or black skin.
Sometimes they sting or hurt. In most cases, hives are caused by an allergic reaction to a medication or food or are a reaction to an irritant in the environment.
In many cases, hives are an acute (temporary) problem that may be alleviated with allergy medications. Most rashes go away on their own. However, chronic (ongoing) cases, as well as hives accompanied by a severe allergic reaction, are larger medical concerns.
Hives are usually caused by an
In some people, histamines can cause swelling, itching, and many of the symptoms that are experienced with hives. In terms of allergens, hives can be
Hives might also be caused by circumstances besides allergies. Its not uncommon for people to experience hives as the result of stress, tight clothes, exercise, illnesses, or infections.
Its also possible to develop hives as the result of excessive exposure to hot or cold temperatures or from irritation due to excessive sweating. Because there are several potential triggers, many times the actual cause of hives cant be determined.
People who are known to have allergies are more likely to get hives. You may also be at risk of developing hives if youre taking medication or if youre unknowingly exposed to things you may be allergic to, such as food or pollen. If youre already ill with an infection or a health condition, you may be more vulnerable to developing hives.
The most noticeable symptom of hives is the welts that appear on the skin. Welts may be red but can also be the same color as your skin. They can be small and round, ring-shaped, or large and of random shape. Hives are itchy, and they tend to appear in batches on the affected part of the body. They can grow larger, change shape, and spread.
Hives may disappear or reappear over the course of the outbreak. Individual hives welts can last anywhere from
Hives can occur in a variety of places on the body. Call 911 or get medical attention immediately if you develop a hives outbreak around your throat or on your tongue or have trouble breathing along with hives.
Hives can occur in response to an allergic reaction or may not have an identifiable cause.
Allergic reactions
The most common causes of hives are allergic reactions. These can be caused by any allergen you might be sensitive to, including:
- foods (such as nuts, milk, and eggs)
- pet dander
- pollen
- dust mites
- insect bites or stings
- medications (primarily antibiotics, cancer drugs, or ibuprofen)
Mild cases of hives caused by allergies are typically treated with long- or short-term allergy medications and avoidance of the trigger.
Anaphylaxis
Anaphylaxis is a severe, life threatening allergic reaction. In this condition, hives are often
Chronic hives
Chronic hives are ongoing cases that dont necessarily have an identifiable cause. Also called chronic urticaria, this condition is marked by recurring hives that can interfere with your daily life. Chronic cases
You may suspect chronic hives if you have welts that dont go away within 6 weeks. While not life threatening, this form of hives can be uncomfortable and difficult to treat. Chronic hives may also be a symptom of an
- an autoimmune disorder
- celiac disease
- lupus
- type 1 diabetes
- rheumatoid arthritis
- thyroid disease
Dermatographism
This form of acute hives is considered mild. Excessive scratching or continuous pressure on the skin causes it. Dermatographism usually clears up on its own in a short period of time without treatment.
Temperature-induced hives
Sometimes changes in temperature can induce hives in people who are sensitive to such changes. Cold-induced hives may occur from cold water or air exposure, while body heat from physical activity may cause exercise-induced hives. Exposure to sunlight or tanning beds may also bring about solar hives in some people.
Infection-induced hives
Both viral and bacterial infections can cause hives. Common bacterial infections causing hives include urinary tract infections and strep throat. Viruses that cause infectious mononucleosis (mono), hepatitis, and colds often cause hives.
The first step in getting treatment is to figure out if you actually have hives. In most cases, a doctor will be able to determine if you have hives from a physical exam. Your skin will show signs of the welts that are linked with hives.
A doctor may also perform blood tests or skin tests to find out what may have caused your hives especially if your hives were the result of an allergic reaction.
You may not need prescription treatment if youre experiencing a mild case of hives not related to allergies or other health conditions. In these circumstances, a doctor might suggest that you find temporary relief by:
Anaphylaxis is a medical emergency that needs to be treated immediately by a physician. If you think you may be experiencing anaphylaxis, contact 911 or your local emergency services.
Simple changes to your lifestyle may be able to help you prevent hives from reoccurring in the future. If you have allergies and you know which substances are likely to cause an allergic reaction, a doctor will suggest that you avoid any possible exposure to these factors. Allergy shots are another option that may help you reduce the risk of experiencing hives again.
Avoid being in high humidity areas or wearing tight clothing if you have recently had a hives outbreak.
Below are some of the most commonly asked questions about hives.
Are hives contagious?
No, hives are not contagious and cant spread from one person to another.
Do hives mean Im allergic to something?
In many cases, hives are the result of an allergic reaction to something you have been exposed to, such as certain medications or pollen. It could also be caused by an infection, stress, or wearing clothes that are too tight. If you have hives that persist for more than a few days, contact a doctor to see if an allergy test is needed to determine the cause of your symptoms.
How long do hives last?
A hives outbreak can last anywhere from
Are there any home remedies for hives?
Yes, there are several home remedies that may help alleviate the symptoms of hives. Taking an antihistamine is one option, as well as taking a cool or lukewarm bath with colloidal oatmeal or baking soda. Avoid hot water, as this may aggravate the hives. Also, try to avoid any potential irritants or allergens that may have caused the hives in the first place.
Although hives can be itchy and uncomfortable, usually theyre not severe and will disappear after a period of time. However, be aware that as some hives go away, new ones may pop up.
Mild cases of hives are considered harmless. Hives can be dangerous if you are having a serious allergic reaction and your throat is swelling. Prompt treatment for a severe case of hives is important for a good outlook.
