IgE vs IgG Allergy Testing: Differences, Accuracy, and Which Test You Need?

Your immune system works as the defense system for your body; it produces antibodies to protect against IgG sensitivities and harmful substances that enter the body, such as allergens, bacteria, and viruses. IgE and IgG are the most significant antibodies produced by the immune system.

If you are confused about IgE vs IgG allergy testing, you have landed on the perfect place. This article explores all about the IgE vs IgG test, the true food allergy differences between the two tests, accuracy, and which test is right for you. So keep reading.

IgE, or Immunoglobulin E, is an antibody that protects your system against problematic parasites and is also responsible for allergic reactions through mast cells. When you consume certain foods such as milk or peanuts, your body considers it harmful for your system and releases histamine that leads to allergic symptoms such as swelling, itching, and breathing issues.

IgG or Immunoglobulin G is responsible for providing long-term defense against infections. This antibody allows your system to remember the harmful substances so that your body can combat them better next time they enter. IgG is usually not associated with allergic reactions.

Knowing the difference between IgE vs IgG testing matters because they offer two different pictures of how your body responds to certain foods and food triggers. IgE is associated with true allergic reactions and food intolerances; on the other hand, IgG is not associated with allergic reactions.

IgE antibodies cause true allergies with immediate reactions leading to symptoms such as swelling, itching, hives, difficult breathing, and anaphylaxis. IgE test results allow better management and emergency treatment.

IgG testing shows if you have been exposed to certain foods. For example, if your IgG result for IgG food is high for milk, it may mean that you often drink milk, not exactly that you are allergic to milk. Understanding the difference between IgE and IgG allows the right diagnosis and helps avoid unnecessary restrictions and worries.

IgE (Immunoglobulin E) is a type of antibody produced by the immune system that is responsible for protecting your body from harmful things such as infections and parasites. IgE can overreact to certain things, detecting them as harmful to your body, causing allergic reactions.

Suppose you eat peanuts and your body mistakes them as a threat for your body, the IgE antibodies respond to it, which causes symptoms even within a few minutes sometimes. IgE test diagnoses allergies to foods, certain medicines, pollen, dust, and insect stings, as well as nasal congestion that causes immediate reactions.

IgE tests detect true allergic reactions that immediately cause symptoms after exposure to the allergen. The common conditions that can be recognized through IgE tests are:

• Food Allergies (milk, peanuts, tree nuts, eggs, shellfish, fish, soy, and wheat)

• Environmental Allergies (pollen, dust mites, mold spores, and pet dander)

• Insect Sting Allergies (bees, wasps, fire ants, and hornets)

• Drug Allergies (certain anesthetics and penicillin)

IgG (Immunoglobulin G) is another type of antibody responsible for long-term defense in the body. It combats the infections and also remembers the previously encountered germs or harmful things.

When it comes to IgE vs IgG allergy, the most common difference is that IgE is associated with immediate reactions, while IgG antibodies are associated with delayed IgG food allergy sensitivities. These types of reactions are visible hours or days after consuming the problematic foods or allergens.

Suppose you eat certain food and your immune system produces IgG antibodies; that’s normal in most people, showing that your body knows its normal food. However, in some cases, the immune system overreacts to certain foods, leading to clinical symptoms, chronic symptoms, and inflammation that may cause delayed symptoms.

Typically, the IgG test is not about diagnosing food allergies but for other medical conditions. Here’s what conditions it may detect:

• Monitoring Immune Health (primary immunodeficiency disorders, severe infections, tracking immune therapies, and recovery after serious illnesses)

• Tracking Past or Ongoing Infections (hepatitis viruses, varicella, measles, mumps, rubella, toxoplasmosis, and COVID-19)

• Examining Inflammatory and Autimmune Conditions (IgG anti TTG for celiac disease, IgG nati-dsDNA for lupus, IgG nati-CCP for rheumatoid arthritis)

IgE vs IgG are both antibodies produced by your immune system, but have different purposes in the context of immunity and allergies.

IgE causes immediate and severe allergic reactions, while IgG causes delayed sensitivities and offers long-term immunity to previous infections.

IgE diagnoses life-threatening allergic reactions that cause immediate symptoms, while IgG detects delayed food sensitivities and immune deficiencies.

IgE is associated with itching, swelling, hives, breathing problems, and anaphylaxis, while IgG is associated with bloating, digestive problems, and fatigue.

IgE testing is accurate for immediate food allergies and severe allergic reactions, whereas IgG testing is accurate for food sensitivities.

What is the difference between IgG and IgE testing? Refer to the below mentioned table below to get a clear picture of IgE vs IgG allergy testing:

• Skin Prick Test (food, dust, pollen, and pet allergies)

• Serum Specific IgE Blood Test (true IgE-mediated allergies)

• Component-Resolved Diagnostics (risk and severity of cross-reactions)

• Total IgG Test (immune function)

• Specific IgG Test (past exposure to viruses, bacteria, and foods)

• Specialized IgG Autoantibody Tests (celiac disease, lupus, and rheumatoid arthritis)

IgE and IgG antibodies explore different things, and using the ideal test is important for the right diagnosis.

True allergies with immediate allergic reactions: If you eat certain food or touch a certain substance and immediately experience an allergic reaction to that. The symptoms involve swelling, hives, itching, wheezing, vomiting, or, in severe cases, anaphylaxis. IgE testing helps detect allergies to foods, dust, pollens, insect stings, and pets.

Chronic digestive or inflammatory symptoms and autoimmune evaluation: In case your doctor needs to check if your immune system remembers the previously experienced infections, such as bacteria, viruses, or vaccines. Moreover, the healthcare professionals advise IgG testing for examining immune system function and to diagnose autoimmune disorders such as digestive issues, lupus, celiac disease, and rheumatoid arthritis.

Sometimes, the healthcare professionals combine IgE and IgG testing to understand your immune response better. It can help recognize certain allergies that may lead to life-harming reactions, monitor immune system function, and assess autoimmune disorders.

When it comes to IgE vs IgG allergy testing, IgE testing is considered highly accurate to diagnose true allergies or immediate allergic reactions. Clinically, these tests are considered reliable for recognizing IgE-mediated allergies. On the other hand, IgG testing is considered less accurate for detecting food allergies, which can sometimes lead to false positives. These tests show the immune memory, immune function, and detect autoimmune antibodies, and allergen exposure, but are not reliable for active allergies.

The IgE blood test measures its levels in the blood, which helps medical professionals get clear insights into the risk of allergy and plan the right treatment.

• High total IgE indicates allergies, parasitic infections, and certain immune disorders.

• Specific IgE levels determine the allergen that acts as a trigger, the severity of allergic reactions, and the risk of fatal reactions such as anaphylaxis.

• Negative specific IgE levels mean no allergy.

• A moderate specific IgE value means the likelihood of allergy.

IgG test reflects previous exposure to infections, foods, or other things, and measuring its levels shows immune system responses and function.

• A high total IgG value indicates strong immune memory and an ongoing, efficient immune response against inflammatory or autoimmune conditions.

• A high specific IgG value may be associated with frequently consumed foods and the likelihood of delayed sensitivity or low-grade immune activity.

IgE vs IgG test cost may vary depending on the city, diagnostic center, laboratory, and other factors. Here’s the price range of IgE and IgG Testing in India, as mentioned below:

Total IgE Test: INR 350 to INR 1100

IgG Test: INR 350 to INR 7500

MyDiagnostics offers IgE and IgG tests at reasonable rates, so book your test now without making a hole in your pocket.

IgE and IgG antibodies offer insights into different aspects of the immune system. IgE testing is used to detect true allergies with immediate reactions, while IgG testing is associated with immune memory. IgE testing recognizes the foods or other substances that cause allergic reactions, and IgG testing recognizes the foods, substances, or germs that your body has already encountered, while also indicating IgG levels.

It's extremely important to understand what is the difference between IgG and IgE testing for accurate diagnosis, the right treatment plan, and avoiding possible complications. Don’t rely on self-diagnosis; instead, consult your healthcare provider or functional medicine practitioners, as certain allergic reactions can be life-threatening if not managed well.

***Medical Disclaimer - The following information is for educational purposes only. No information provided on this website, including text, graphics, and images, is intended as a substitute for professional medical advice. Please consult with your doctor about specific medical advice about your condition(s).