What do allergic reaction

You can have an allergic reaction after inhaling, eating, or touching an allergen. Doctors can also use allergens to diagnose allergies and can even inject them into your body as a form of treatment. Allergies appear to run in families, which means they can be inherited. The reasons why allergies develop are unclear, but some substances are known to commonly cause an allergic reaction. People who have allergies are typically allergic to one or more of the following:.

The symptoms of an allergic reaction can vary from mild to severe. If you become exposed to an allergen for the first time, your symptoms may be mild. These symptoms may get worse if you repeatedly come into contact with the allergen. Severe allergic reactions usually to foods, insect stings, and medications can cause the following symptoms:. A severe and sudden allergic reaction known as anaphylaxis can develop just seconds after exposure to an allergen.

This type of reaction results in life threatening symptoms, including:. If you experience anaphylaxis, seek immediate emergency help. Without treatment, anaphylaxis can result in death. A primary care physician or an allergist can diagnose allergic reactions.

If you experience symptoms of an allergic reaction, the doctor will perform an exam and ask you about your health history. If your allergic reactions are severe, they may ask you to keep a journal that details your symptoms and the substances that appear to cause them. Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.

Adults and older children often have several symptoms of shock. Shock is a life-threatening condition that may occur quickly after a sudden illness or injury. Babies and young children often have several symptoms of shock. Based on your answers, the problem may not improve without medical care. Based on your answers, you may need care soon.

The problem probably will not get better without medical care. Based on your answers, you may need care right away. The problem is likely to get worse without medical care. Based on your answers, you need emergency care. Call or other emergency services now. If you have an epinephrine shot, use it while you wait for help to arrive. Follow the directions on the label about how to give the shot.

Sometimes people don't want to call They may think that their symptoms aren't serious or that they can just get someone else to drive them. But based on your answers, the safest and quickest way for you to get the care you need is to call for medical transport to the hospital.

You can use home treatment to relieve symptoms of:. Try a non-prescription medicine for the relief of itching, redness, and swelling. Be sure to follow the non-prescription medicine precautions.

For tips on how to treat dry and irritated skin, see the topic Dry Skin and Itching. For information on how to treat an insect bite or sting, see the topic Insect Bites and Stings and Spider Bites. Call your doctor if any of the following occur during home treatment:.

To prevent problems with severe allergic reactions:. To prevent seasonal or year-round allergy reactions:. You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:. This information does not replace the advice of a doctor.

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Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. British Columbia Specific Information Symptoms of a severe allergic reaction Anaphylaxis can start within minutes of eating or exposure to an allergen a substance capable of causing an allergic reaction.

Topic Overview Allergies are an overreaction of the body's natural defence system that helps fight infections immune system. Types of allergies There are many types of allergies. Some of the more common ones include: Food allergies, which are more common in children than adults. Food allergies are most common in people who have an inherited tendency to develop allergic conditions. These people are more likely to have asthma and other allergies. For more information, see the topic Food Allergies.

Medicine allergies. Many prescription and non-prescription medicines can cause an allergic reaction. Allergic reactions are common and unpredictable. The seriousness of the allergic reaction caused by a certain medicine will vary.

Allergies to insect venom. When you are stung by an insect, poisons and other toxins in the insect's venom enter your skin. It is normal to have some swelling, redness, pain, and itching at the site of a sting. An allergic reaction to the sting occurs when your body's immune system overreacts to the venom of stinging insects. For more information, see the topic Allergies to Insect Stings. Allergies to animals , which are more likely to cause breathing problems than skin problems.

You may be allergic to your pet's dead skin dander , urine, dried saliva, or hair. Allergies to natural rubber latex. Some people develop allergic reactions after repeated contact with latex, especially latex gloves. Allergies that develop from exposure to a particular inhaled substance in the workplace.

These are called occupational asthma. Allergies to cosmetics, such as artificial nails, hair extensions, and henna tattoos. Health Tools Health Tools help you make wise health decisions or take action to improve your health. Decision Points focus on key medical care decisions that are important to many health problems. Actionsets are designed to help people take an active role in managing a health condition. Check Your Symptoms Are you concerned about an allergic reaction? How old are you?

Less than 12 years. Are you male or female? Why do we ask this question? The medical assessment of symptoms is based on the body parts you have. If you are transgender or non-binary, choose the sex that matches the body parts such as ovaries, testes, prostate, breasts, penis, or vagina you now have in the area where you are having symptoms.

If you have some organs of both sexes, you may need to go through this triage tool twice once as "male" and once as "female". This will make sure that the tool asks the right questions for you. Could you be having a severe allergic reaction? This is more likely if you have had a bad reaction to something in the past. Do you have symptoms of shock? The symptoms in an adult or older child are different than the symptoms in a young child.

Reviewed by: Larissa Hirsch, MD. Larger text size Large text size Regular text size. What Is Anaphylaxis? Anaphylaxis pronounced: an-eh-fil-AK-siss most often happens during allergic reactions to: foods insect stings medicines latex Anaphylaxis can be scary.

But being prepared will help you treat a reaction quickly. Allergic reactions can cause: trouble breathing throat tightness or feeling like the throat or airways are closing hoarseness or trouble speaking wheezing nasal stuffiness or coughing nausea, belly pain, vomiting, or diarrhea trouble swallowing fast heartbeat or pulse skin itching, tingling, redness, or swelling hives a feeling like something bad is about to happen pale skin passing out Anaphylaxis can cause different symptoms at different times.

It's considered anaphylaxis if someone has: any severe symptoms, such as trouble breathing, repeated vomiting, passing out, or throat tightness or two or more mild symptoms, such as hives and vomiting or coughing and belly pain The person needs treatment right away.

How Is Anaphylaxis Treated? What to Do if You Have Anaphylaxis Give yourself epinephrine right away if you start to: have trouble breathing feel tightness in your throat feel faint have two or more milder allergic symptoms together like hives with coughing Don't try to use an inhaler or antihistamine and wait to see what happens.

If you have signs of a serious allergic reaction: Use the epinephrine auto-injector right away. Follow up with your doctor and ask about allergy testing , he advises. Testing can help pinpoint the cause of your reaction, and help you avoid triggers and future reactions. Most cases are mild, but some reactions are life-threatening, so you may need to act quickly.

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