Different Types and Causes of Allergic Reactions

Your immune system is responsible for defending 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 are even injected as a form of treatment.

What causes allergic reactions?

Getting to know allergic reactions

Doctors don't know why some people have allergies. Allergies appear in the family (deceased). If you have a close family member who has an allergy, you will have a greater risk of experiencing allergies.

Although the reason for the allergy is 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 peanuts 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 are repeatedly exposed to allergens.

Symptoms of a mild allergic reaction can include:
  • Red spots (red itchy spots on the skin)
  • Itchy
  • Nosed nose (rhinitis)
  • Rash
  • Eyes watery or itchy

A severe allergic reaction can cause other symptoms such as:
  • Abdominal cramps or pain
  • Pain or tightness in the chest
  • Diarrhea
  • Trouble swallowing
  • Dizziness (vertigo)
  • Fear or anxiety
  • Blushing face
  • Nausea or vomiting
  • Heart palpitations
  • Swelling of the face, eyes, or tongue
  • Weakness
  • Many
  • Hard to breath
  • Unconsciousness

A severe and sudden allergic reaction can develop within seconds after being exposed to an allergen. This type of reaction is known as anaphylaxis and is a life-threatening symptom, including swelling of the respiratory tract and an inability to breathe and a sudden dramatic decrease in blood pressure. If you experience this allergic reaction, seek emergency help immediately. Without treatment, this condition can result in 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 conduct 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 seem 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 (a type of elimination)
  • Blood test

A skin test is done by applying a small amount of suspected allergen to the skin and watching the reaction. An allergen substance may be applied to the skin (patch test), applied to a small puncture in the skin (prick test), or injected under the skin (intradermal test). The most useful skin test to diagnose:
  • Food allergies
  • Fungal allergies, pollen, and animal hair allergies
  • Penicillin allergy
  • Poison allergies (such as poisons from mosquito bites or bee stings)
  • Allergic contact dermatitis (a rash that you get from touching a substance)

Challenge tests are useful in diagnosing food allergies. This test involves reducing food from your diet for several weeks and watching the symptoms that occur when you eat the food again.

Blood tests are allergy tests on your blood to check for possible antibodies against allergens. Antibodies are your body's proteins that are produced to fight harmful substances. Blood tests are used when a skin test does not help or cannot be done.

How to treat allergic reactions?

If you experience an allergic reaction and you don't know what causes it, you may need to see your doctor determine what your allergies are. If you have allergies and experience symptoms that are recognized, you may not need to seek medical attention if the symptoms are mild. In most cases, antihistamines on the market can effectively control mild allergic reactions.

If you or someone you know has a severe allergic reaction, you should seek emergency medical attention. Check whether the person is breathing, take him to the hospital, and give cardiopulmonary resuscitation (CPR) if needed. People with severe allergies often carry emergency drugs with them like EpiPen, which injects epinephrine drugs. Epinephrine opens the respiratory tract and increases blood pressure. This drug is called a rescue drug. If the person is unable to use the medicine, help him or her use it. If the person is not aware, you must:
  • Lay the person flat on his back
  • Lift the person's foot
  • Cover people with blankets
  • This method will help prevent shock.

How to prevent allergic reactions?

You might 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 allergies, you can:
  • Avoiding allergen exposure
  • Seek medical treatment if you have allergens
  • Bring medication to treat anaphylaxis