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How severe can allergy reactions become?

Verified By Dr Vijendran Pragasam February 11, 2021 13945 0
allergic reaction

The human body may be allergic to a variety of substances. The list of common allergic substances is large and can include food ingredients, pets, and pollen. Our body’s reaction to the substance causing the allergy also varies largely. Unfortunately, most allergies cannot be treated. However, they can be managed through a variety of treatments.

One of the most severe allergic reactions is known as anaphylactic shock. This is when your immune system goes into overdrive as a reaction to an allergen and can cause serious problems. In some cases, the anaphylactic reaction can even be fatal. It is important for you to seek immediate medical help if you are experiencing a severe allergic reaction.

What is an allergic reaction?

The immune system in our body is designed to protect us from foreign objects like germs and bacteria. It chiefly consists of antibodies that function as the defenders . In case of allergies, your immune system identifies certain allergens as harmful, even if this is not the case. The immune system produces the antibodies specific to these allergens and tries to protect your body from them. These antibodies can cause inflammation of the skin, sinuses, digestive system, and airways.

It is important to note that the severity of the body’s immune system’s reaction to an allergen varies from person to person. The reaction can range from mild irritation to a life-threatening medical emergency.

Allergies can include a variety of substances and are dependent on the individual’s immune system.

What are the types of allergic reactions?

Allergic reactions are classified as follows:

  • Type I – Immediate hypersensitivity 
  • Type II – Cytotoxic reaction
  • Type III – Immune complex reaction
  • Type IV – Cell-mediated or delayed hypersensitivity

What causes allergic reactions?

When your body is exposed to allergens, the immune system releases a host of chemicals, including histamines, which causes the symptoms of allergy.

The common triggers of allergies include:

  • Foods like peanuts, shellfish, wheat, soy, milk, and eggs
  • Airborne allergens like dust, pollen, and mold
  • Insect stings
  • Medications
  • Allergies caused by touching substances like dust or latex

Learning to identify the symptoms of an allergic reaction is crucial to learning how to manage the reaction.

What are the symptoms of an allergic reaction?

An allergic reaction can affect different parts of your body to varying degrees of severity based on the allergen. Typically, allergic reactions affect the digestive system, skin, nasal passage, airways, and sinuses. It is easier to understand the symptoms of allergies by focusing on the area affected.

In the case of allergic rhinitis, also known as hay fever, you may experience:

  • Sneezing
  • Runny or stuffy nose
  • Itchiness of the nose, eyes, roof of the oral cavity
  • Watery eyes accompanied by redness or swelling

Food allergies can cause the following symptoms:

  • Swelling of the tongue, face, lips, throat
  • Tingling of the mouth
  • Hives
  • Anaphylaxis – a life-threatening reaction which is a medical emergency

Allergies caused by an insect sting include:

  • Swelling at the site of the sting
  • Hives or itching all over the body
  • Tightening of the chest resulting in wheezing or coughing

Some people might be allergic to particular medications. The symptoms caused by an allergic reaction to medicines include:

  • Itchy skin
  • Hives
  • Swelling of the face
  • Rashes
  • Wheezing
  • Anaphylaxis

The skin is also susceptible to allergic reactions, typically known as atopic dermatitis or eczema. The symptoms of this condition include:

  • Reddening of the skin
  • Itchiness
  • Flaking or peeling

What makes anaphylaxis so serious?

Anaphylaxis is a life-threatening condition that can send your body into shock. It is an extreme reaction to an allergen, which can include foods and insect bites. If this condition is left untreated, it can even be fatal. The symptoms of anaphylaxis include the following:

  • Nausea and vomiting – Anaphylaxis can present itself as extreme nausea and vomiting.
  • A weakened pulse – A rapid and weakened pulse can result in severe heart related disorders .
  • Loss of consciousness
  • Skin rash – Your skin can erupt in hives due to an anaphylactic shock.
  • Severe shortness of breath – Many people with severe allergic reactions will experience their airways swelling up to the point where they cannot get in enough air.
  • Lightheadedness – Due to the difficulty in breathing, your brain can be deprived of oxygen, making you feel dizzy or lightheaded.

If you are experiencing symptoms of anaphylaxis, it is crucial that you seek immediate medical attention. Anaphylaxis can be fatal if left untreated.

When should you see a doctor?

In case of an anaphylactic reaction, please call your local emergency number for immediate medical attention. It is recommended that you have an epinephrine auto-injector handy, which you can administer yourself to abate the symptoms. However, you must still visit the emergency room to ensure that the symptoms are managed once the effects of the epinephrine wear off.

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What are the risk factors of an allergic reaction?

Allergies can affect anyone depending on their environmental factors and genetics. However, certain factors put you at a higher risk of allergies. These factors include:

  • A family history of allergies
  • A history of asthma
  • Young children are more susceptible to allergies

What are the potential complications of an allergic reaction?

Severe allergies can put you at risk for further complications. These include:

Allergic reactions can cause long-term harm to your health. It is crucial to know how to prevent them.

How to prevent an allergic reaction?

While it is not entirely possible to avoid an allergic reaction, especially if you are prone to allergies, there are certain measures you can take to help you better manage the condition. These are:

  • Maintain a diary of all your known triggers. This can help your doctor devise a better treatment plan for you.
  • Avoid all known triggers. This can include avoiding certain foods you are allergic to or avoiding going outside during pollen season.
  • Wear a medical bracelet. This can help save crucial minutes during an emergency and help you get the medical attention you require.

How is an allergy diagnosed?

A doctor will conduct a physical examination and ask for a detailed medical history. They might also ask you to keep a diary tracking all your allergic reactions and trace it back to a particular allergen. A more accurate way to identify allergens is a skin test. Here, the doctor will make small pricks on your skin and expose the cuts to common allergens. If your skin displays allergic reactions to the substances after a period of time, then you might be allergic to the substance.

Your doctor might also prescribe a blood test to measure the allergy-causing antibodies in your blood. The blood sample can be tested against known allergens to find what you are allergic to.

Allergies can be treated in a variety of ways.

How are allergies treated?

The best way to prevent allergic reactions is to avoid any and all known allergens. In mild cases of allergies, over-the-counter medications like antihistamines can help subside the symptoms of an allergy. However, if you have sustained allergic reactions that cannot be controlled by OTC medications, your doctor might devise a more intensive  treatment plan. This can include:

  • Immunotherapy. This treatment involves exposing your body to small doses of your known allergen over a period of a few years. Doing so teaches your body to be less sensitive to the allergen and thus reduces the production of the anti-allergen antibodies.
  • Epinephrine. Your doctor might ask you to carry an emergency epinephrine auto-injector if you have a severe allergy. In case of a serious reaction, you can administer the shot to yourself, which will stop the reaction for a while, where you can get emergency medical attention.

Talk to your doctor about the various options available to treat your allergies. You will have to work with them closely in order to develop a treatment plan that is best suited for you.


Allergic reactions can range from mild to extremely severe. If you notice that you are showing the symptoms of an allergy, then it is best to consult with a doctor. Allergies must be managed before they develop into more serious conditions. Immunologists at Apollo Hospitals are trained to help you manage your allergies.

Here are a few common FAQs about allergic reactions.

Frequently Asked Questions (FAQs)

1. How long does an allergic reaction last?

An allergic reaction typically lasts between 12 hours to 3 days. However, you can experience the symptoms for up to 4 weeks, even with medications.

2. What does an allergic rash look like?

You will see hives or red bumps on your skin as soon as it comes in contact with the allergen. The hive will begin at the point of contact and then radiates outward.

3. Can I suddenly develop an allergy? Most allergies develop at any time during a person’s life. You might find that certain foods or allergens are causing allergic symptoms currently  while they didn’t produce the same reaction before.

Verified By Dr Vijendran Pragasam
MBBS, MD ( Dermatology & Leprosy & Venereolgy), DNB (Dermatology & Venereolgy), Consultant Dermatologist, Apollo Hospitals, Sheshadripuram, Bengaluru

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