How long will I have hives after an allergic reaction
How long can hives last?
Hives can appear and disappear quickly, with each hive only lasting around 23 hours. However, depending on the cause, they may reappear and continue affecting someone for days, weeks, or longer.
People can have acute hives, which occurs due to a specific trigger and resolves within
This article looks at how long hives last, factors that influence their duration, and treatment.
Each hive lasts only
Acute hives appear quickly and do not last long. Doctors classify hives as acute if the overall duration is less than 6 weeks.
However, around 25% of people go on to develop chronic hives. This is when hives regularly reappear over 6 weeks or more.
For many individuals, chronic hives eventually clear on their own, but this can take months. According to the American Academy of Dermatology Association (AAD), around half of people with chronic hives spontaneously recover within 1 year.
Acute hives often occur in response to an allergen or irritant. When the immune system perceives a substance as a threat, it releases histamine and other chemicals. This causes tiny blood vessels under someones skin to leak fluid, which accumulates and causes the bump.
Some
- food allergens, such as milk, eggs, tree nuts, peanuts, or shellfish
- contact allergens, such as latex or animal dander
- insect bites or stings
- medications
Any drug can cause hives, but some of the medications most commonly associated with this symptom include:
Acute hives can also occur in response to viral infections, parasitic infections, or during times of stress.
According to a 2018 review, doctors are unsure of the cause of acute hives in
Chronic hives may have the same cause as acute hives, but with symptoms lasting longer than 6 weeks. However, chronic hives are often not due to an allergen and instead have a physical cause.
There are two subcategories of chronic hives: inducible urticaria and chronic idiopathic urticaria.
Chronic idiopathic hives
Chronic idiopathic urticaria has no clear cause and is the most common form of chronic hives. Researchers are working to understand why this type of hives occurs, but a leading theory links it with autoimmunity.
Autoimmunity occurs when a persons immune system mistakenly attacks healthy tissue, and several autoimmune conditions are associated with chronic hives. The most common is thyroid disease, which is present in
This suggests that the hives may result from someones immune system not functioning as it should. Other conditions that can occur alongside chronic hives include type 1 diabetes, lupus, and rheumatoid arthritis.
Infections can also be associated with the onset of chronic hives. This includes bacterial, viral, and parasitic infections. Again, this may result from autoimmunity an infection may trigger a change in how the persons immune system works.
Inducible hives
Inducible or physical urticaria is less common than chronic idiopathic urticaria. With this subtype, it is possible to purposely induce the hives by a person exposing their skin to certain triggers, which could include:
- Scratching or pressure: The
most common type of inducible hives is known as dermatographia. This condition involves developing hives as a response to scratching or drawing on the skin. - Cold: Cold hives occur on someones skin or mouth after exposure to cold temperatures. Triggers include consuming iced drinks, touching cold water, or going outside in cold weather.
- Heat: Cholinergic hives occurs when an individuals body becomes hot or sweaty. Hot baths, exercise, and spicy food can be triggers.
- UV light: Solar hives occur in response to UV light from the sun and certain light bulbs, such as those in tanning beds.
- Water: Some people develop hives if their skin comes into contact with water. This is known as aquagenic urticaria and is very rare.
Doctors diagnose hives by performing a physical examination. There is no test to determine whether the persons hives are acute or chronic, so they will use the length of time they recur to do this.
The doctor may also ask an individual:
- when the rash began
- the shape, size, and distribution of the rash
- where on the body they first noticed the rash
- if they have had any insect bites
- if they live or work with common hive triggers, such as chemicals, animals, or latex gloves
- if they have bone or joint pain, fever, or abdominal pain
- if anyone in their family experiences hives
- if they take any medications or supplements
The doctor may use a skin prick test and serum-specific IgE test to check if the acute hives result from a specific substance, such as food, dust mites, or chemicals. Alternatively, they may refer someone to an allergy clinic for these tests.
However, in cases of chronic hives, allergy testing is rarely useful. A doctor may check for other underlying health conditions by performing additional tests, such as:
The most suitable treatment depends on whether the person has acute hives or chronic hives.
Acute hives
Doctors typically recommend second-generation antihistamines as the first-line treatment for acute hives, such as:
- loratadine (Claritin)
- desloratadine (Clarinex)
- fexofenadine (Allegra)
- cetirizine (Zyrtec)
- levocetirizine (Xyzal)
They may prescribe a standard dose or increase by up to 4 times if the individual does not respond.
If these medications do not improve symptoms, the doctor may recommend an additional antihistamine, such as cimetidine (Tagamet), famotidine (Pepcid), or ranitidine (Zantac). They may recommend a 310-day course of corticosteroids to help control the symptoms in severe cases.
The doctor may prescribe an epinephrine auto-injector if they think the individual is at risk of anaphylaxis, which is a severe allergic reaction that restricts breathing. This provides emergency medicine to treat anaphylaxis quickly.
The doctor will then reassess the individual in 26 weeks.
Chronic hives
Doctors may recommend a four-step treatment plan for chronic hives. This approach involves using an antihistamine daily, which may be up to 4 times the regular dosage depending on how the individual responds.If necessary, they may prescribe a second antihistamine or another medication, such as montelukast (Singulair). With persistent hives, they may suggest a high potency antihistamine, such as hydroxyzine or doxepin.
The final step is for a doctor to refer the individual to a specialist for immunomodulatory therapy. This may involve taking medications such as omalizumab (Xolair) or cyclosporine (Sandimmune).
Once symptoms are under control, a doctor may gradually reduce the dosage of these medications. If the hives have an identifiable cause, such as cold or heat exposure, adopting changes to avoid the triggers wherever possible is also important.
The AAD suggests the following methods for people to reduce irritation and itchiness in hives:
- applying topical anti-itch medications, such as calamine lotion
- wearing loose-fitting clothing
- moisturizing with fragrance-free lotion to prevent dry skin
- using cold compresses several times per day
However, it is important for individuals to try to determine whether the hives have a specific trigger, in addition to relieving symptoms. If someone has cold hives, for example, a cold compress may make them worse.
Therefore, it is a good idea for people to keep a symptom diary, recording when the hives occur and any factors that might have contributed. Symptom diaries are also useful to refer to at medical appointments. A person can take note of:
- the date and time the hives appear
- what they were doing just before they developed
- what they have had to eat or drink
If any common factors emerge when the hives occur, a person can try to temporarily avoid these to see if it helps. It is important for people to do this with the guidance of a doctor, allergist, or dietitian if someone has food-related hives.
Learn more about remedies and treatments for hives here.
Hives do not last long, taking only 23 hours to fade. However, more can appear, which makes the symptoms last longer. Acute hives can develop and resolve on their own within 6 weeks, while chronic hives can last much longer.
Doctors treat acute and chronic hives differently, so it is advisable for people to speak with a medical professional about this symptom, especially if the hives last longer than 6 weeks.
If hives or swelling occur in the mouth and airways, making it difficult to breathe, dial 911 or the number of the nearest emergency department immediately.
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
