What is an allergic reaction?
Your immune system is responsible for maintaining the body against bacteria and viruses. In some cases, your immune system will fight substances that normally do not pose a threat to the human body. These substances are known as allergens, and when your body reacts to them, this causes an allergic reaction. Allergens that cause reactions can be in contact with skin, inhaled, or eaten. Allergens can also be used to diagnose allergies and even be injected as a form of treatment.
What causes allergic reactions?
Doctors don't know why some people have allergies. Allergies appear in the family (decreased). If you have close family members who have allergies, you will have a greater risk of allergies.
Although the reasons for allergies are unknown, there are several substances that often cause allergic reactions. People who have allergies are usually allergic to one or more of the following:
- Pet fur
- Bee stings or bites from other insects
- Certain foods, including beans or shellfish
- Certain drugs such as penicillin or aspirin
- Certain plants
- Pollen
What are the symptoms of an allergic reaction?
The symptoms of an allergic reaction can vary from mild to severe. If you get allergens for the first time, symptoms may be mild. These symptoms may be worse if you repeatedly get allergens.
Symptoms of a mild allergic reaction can include:
- Red spots (itchy red spots on the skin)
- Itchy
- Nasal congestion (rhinitis)
- Rash
- Watery or itchy eyes
Severe allergic reactions can cause other symptoms such as:
- Cramps or abdominal pain
- Pain or tightness in the chest
- Diarrhea
- Difficulty swallowing
- Dizziness (vertigo)
- Fear or anxiety
- Blushing face
- Nausea or vomiting
- Heart palpitations
- Swelling of the face, eyes, or tongue
- Weakness
- Wheezing
- Hard to breath
- Unconsciousness
A severe and sudden allergic reaction can develop within a few seconds of getting an allergen. This type of reaction is known as anaphylaxis and is a life-threatening symptom, including swelling of the respiratory tract and inability to breathe and sudden dramatic decrease in blood pressure. If you experience this allergic reaction, seek emergency help immediately. Without treatment, this condition can lead to death within 15 minutes.
How to diagnose an allergic reaction?
Allergic reactions can be diagnosed by your doctor. If you experience symptoms of an allergic reaction, the doctor will do an examination and ask about your medical history. If your allergic reaction is severe, your doctor may ask you to keep a detailed journal of what symptoms and substances appear to cause your allergies. Your doctor may want to order a test to determine what is causing your allergy. The most common types of allergy tests are:
- Skin test
- Challenge test (type of elimination)
- Blood test
Skin tests are carried out by applying a small amount of suspected allergens to the skin and monitoring the reaction. The substance of the allergen may be affixed to the skin (patch test), applied to a small puncture on the skin (puncture test), or injected under the skin (intradermal test). The most useful skin tests for diagnosing:
- Food allergy
- Fungal allergies, pollen, and animal fur allergies
- Penicillin allergy
- Toxic allergies (such as poisons from mosquito bites or bee stings)
- Allergic contact dermatitis (the rash you get from touching a substance)
Challenge tests are useful in diagnosing food allergies. This test involves reducing a food from your diet for several weeks and watching for symptoms that occur when you eat the food again.
A blood test is an allergy test in your blood to check for possible antibodies that fight allergens. Antibodies are proteins of your body that are produced to fight harmful substances. Blood tests are used when skin tests are not helpful or cannot be done.
How to treat allergic reactions?
If you experience an allergic reaction and you don't know what caused it, you may need to check with your doctor to determine what your allergies are. If you have allergies and experience recognizable symptoms, you may not need to seek medical treatment if symptoms occur mildly. In most cases, commercially available antihistamines can effectively control mild allergic reactions.
If you or someone you know has a severe allergic reaction, you should seek emergency medical attention. Check if the person is breathing, take it to the hospital, and give cardiopulmonary resuscitation (CPR) if needed. People with severe allergies often carry emergency medicine with them such as EpiPen, who injects epinephrine. Epinephrine opens the respiratory tract and increases blood pressure. This drug is called a rescue drug. If the person is unable to use the drug, help him or her to use it. If the person is unconscious, you must:
- Lay the person flat on his back
- Lift the person's leg
- Cover people with blankets
- This method will help prevent shock.
How do you prevent allergic reactions?
You may not be able to prevent an allergic reaction. But there are steps you can take to prevent allergic reactions in the future. After you identify your allergy, you can:
- Avoid exposure to allergens
- Seek medical care if you have allergens
- Bring medicine to treat anaphylaxis