What causes hives besides allergies
The symptoms of a severe allergic reaction (anaphylaxis) can be sudden and get worse extremely quickly.
Initial symptoms of anaphylaxis are often the same as those listed above and can lead to:
- breathing difficulties
- trouble swallowing or speaking
- tight chest
- swollen tongue
- feeling dizzy or faint
Anaphylaxis is a medical emergency. Without quick treatment, it can be life threatening.
If you ponder you or someone you know is experiencing anaphylaxis, dial 999 and enquire for an ambulance as soon as possible.
Some children can own a mixed reaction where they experience both IgE symptoms, such as swelling, and non-IgE symptoms, such as constipation.
This can happen to children who own a milk allergy.
Autoimmune Urticaria (Hives)
Mast cells are the cells in the skin and mucous membranes that contain histamine. Release of histamine causes the allergic symptoms of hives and angioedema (swelling of large areas of the body).
Itching is a common symptom when histamine is released. Anti-histamines are often prescribed to assist control this symptom.
The immune system normally protects us by making antibodies against foreign invaders such as bacteria and viruses.
These antibodies are called IgG and are often referred to as gammaglobulins. Generally, IgG is not formed to any normal body tissue but occasionally, by error, this does happen. If antibody binds to normal tissues it can cause damage to the body or create other disease symptoms. Rheumatoid arthritis is a excellent example of an autoimmune disease. Antibodies that react with body tissues are felt to contribute to joint swelling and pain. Numerous other common diseases are caused by autoimmunity such as juvenile diabetes and low thyroid disease.
It has been recently discovered that some persons who suffer with hives or angioedema also own an autoimmune disease.
In these cases, autoantibodies own been formed that bind to the Fc-receptor on mast cells. The normal function of the Fc-receptor is to anchor allergic antibodies, called IgE, to the mast cell surface (see the mast cell diagram below).
IgE is formed in allergic persons and binds specifically to allergens in the environment. When airborne allergens land on nasal tissues or eye conjunctiva, or are eaten (foods) and enter the body through the intestinal tract they bind to the specific IgE. As a result of this interaction, a signal is sent by the IgE antibody to the mast cell causing it to release its histamine. Histamine release causes the nasal and eye symptoms seen in those who suffer with «hay fever» and can produce hives, angioedema, or even life-threatening symptoms such as respiratory compromise or low blood pressure.
In persons with autoimmune hives, the IgG autoantibody that binds to the Fc-receptor tricks the mast cell into believing that the IgE on its surface has encountered an allergen.
When this happens, hives or tissue swelling can result. (The diagram above shows a Mast cell with purple histamine granules. The «patient IgG» is the autoantibody that binds to the Fc-receptor.)
Once it has been discovered that the anti-IgE Fc-receptor antibody is present in a patient’s blood, it is no longer necessary to glance for any other cause for hives. Why this autoantibody triggers hives only intermittently is unknown. Numerous people with this autoantibody feel that their hives are more likely to happen when they are stressed.
Some women feel that hormonal changes that happen just prior to their menstrual periods also trigger their hives. Some medications, especially aspirin, ibuprofen (Advil), or naproxsen (Aleve) are also more likely to trigger hives. However, Tylenol (acetominophen) does not generally trigger hives or swelling.
Once the diagnosis of autoimmune hives has been made, the goal is then to select the best combination of medications to reduce the frequency of outbreaks.
Long-term, this autoantibody may go into remission and it may be reasonable to attempt periods off suppression medications every few month to see if they are still needed.
There has been a high incidence of autoantibody to thyroid glands reported among those with anti-Fc-receptor antibodies and it is suggested that annually thyroid testing be done by the primary care physician.
en españolAyuda con la urticaria
What Are Hives?
Hives are pink or red bumps or slightly raised patches of skin.
Sometimes, they own a pale middle. Hives generally itch, but they also can burn or sting.
Hives can happen anywhere on the body. They can be tiny or as large as a dinner plate. The spots also might glance love rings or groups of rings joined together in clusters.
Hives can change locations in a matter of hours. A bunch of hives might be on a person’s face, then go away. Later, more may appear on the person’s arms.
Hives are common and generally harmless.
But occasionally they’re a sign of a serious allergic reaction. So, always tell your mom or dad if you get them.
The medical term for hives is urticaria (say: ur-tuh-KAR-ee-uh).
When a person is exposed to something that can trigger hives, certain cells in the body release histamine (say: HIS-tuh-meen) and other substances. This causes fluid to leak from the little blood vessels under the skin. When this fluid collects under the skin, it forms the blotches, which we call hives.
What Will the Doctor Do?
Doctors generally can diagnose hives just by looking at you and hearing your tale about what happened. The doctor can attempt to assist figure out what might be causing your hives, although often the cause will remain a mystery.
If you’re getting hives a lot, or your reaction was serious, your doctor might send you to another doctor who specializes in allergies.
Sometimes, doctors will propose you take a type of medicine called an antihistamine to relieve the itchiness. In numerous cases, hives clear up on their own without any medication or doctor visits.
Less often, hives can be a sign of a more serious allergic reaction that can affect breathing and other body functions. In these cases, the person needs immediate medical care.
Some people who know they own serious allergies carry a special medicine to use in an emergency.
This medicine, called epinephrine, is given by a shot. Generally, a nurse gives you a shot, but because some allergic reactions can happen really quick, numerous adults and kids carry this emergency shot with them and know how to use it, just in case they ever need it in a hurry.
Why Do I Get Hives?
People can get hives for lots of diverse reasons (though sometimes, the cause is not known).
One common reason for getting hives is an allergic reaction. Some common allergic triggers are certain foods (like milk, wheat, eggs, shellfish, berries, and nuts), medicines (such as antibiotics), and insect stings or bites.
Other causes of hives are not related to allergies and these can include:
- nervousness or stress
- exposure to the freezing (like diving into a freezing pool)
- sun exposure
- infections caused by viruses
No matter what the cause, a case of hives can final for a few minutes, a few hours, or even days.
Can I Prevent Hives?
Yes and no.
The answer is «yes» if you know what causes your hive. If you know something causes you trouble, you can attempt to avoid it. If you get hives when you’re nervous, relaxation breathing exercises may assist. But if you don’t know why you get hives, it’s tough to prevent them.
Some kids get hives when they own a virus, such as a bad freezing or stomach flu.
Other than washing your hands regularly, there’s not much you can do to avoid getting ill occasionally.
The excellent news is that hives generally aren’t serious and you might even grow out of them. Who wouldn’t desire to give hives the heave-ho?
Penicillin allergies are the most common drug allergy and a common cause of skin rashes, but it is hard to know if that's what's causing this rash. It might be caused by something else.
Exercise-induced food allergy
In some cases, a food allergy can be triggered after eating a certain food and then exercising.
This can lead to anaphylaxis in severe cases, sometimes known as food-dependent exercise-induced anaphylaxis.
Drinking alcohol or taking an non-steroidal anti-inflammatory drug (NSAID) such as aspirin or ibuprofen may also trigger an allergy in people with this syndrome.
Sheet final reviewed: 15 April 2019
Next review due: 15 April 2022
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Non-IgE-mediated food allergy
Another type of allergic reaction is a non-IgE-mediated food allergy. The symptoms of this type of allergy can take much longer to develop – sometimes up to several days.
Some symptoms of a non IgE-mediated food allergy may be what you would expect to see in an allergic reaction, such as:
- redness and itchiness of the skin – although not a raised, itchy red rash (hives)
- the skin becomes itchy, red, dry and cracked (atopic eczema)
Other symptoms can be much less obvious and are sometimes thought of as being caused by something other than an allergy.
- vomiting with or without diarrhoea
- abdominal cramps
- in babies: excessive and inconsolable crying, even though the baby is well fed and doesn’t need a nappy change (colic).
Symptoms of a Penicillin Allergy
A penicillin allergy can cause life-threatening allergic reactions, but fortunately, most kids with a penicillin allergy own more mild reactions, leading to simple skin rashes such as hives.
Children with more severe symptoms will experience hives as well as wheezing, difficulty breathing or swallowing, or swelling in their mouth or throat, as well as anaphylaxis—a serious allergic reaction.
How Anaphylaxis Is Treated
If your kid just has hives (also called urticaria), you will likely notice red or pink raised areas on your child's skin that are itchy, varied in size, and come and go over several hours. They often don't go away completely, though.
Instead, older hives go away in one part of your child's body, while new ones continue to appear somewhere else. Any individual hive shouldn't final more than 24 hours. If it does, then your kid may own a similar skin rash, such as erythema multiforme, and not simple hives.
Erythema multiforme is a type of allergic reaction that can also be caused by a penicillin allergy or things love other drugs, bacterial infections, or viral infections. Unlike hives, which come and go, the rash from erythema multiforme generally continues to spread and may final for one to two weeks.
Other symptoms of erythema multiforme can include fever, joint aches, mouth sores, and red eyes.