Do you have an Allergy or Sensitivity?

Many people do not know the difference between an allergy and a sensitivity. Don’t worry, you’re not alone. Defining or identifying a sensitivity can be difficult, but with Lifelab Testing, we analyse your blood to find out whether you have an allergy or a sensitivity.
Allergy
An allergy is the body’s immune system responding to what would normally be considered a harmless substance. But what are these substances? These substances include many things which we come across on a daily basis, including pollen, food, mould, pet’s hair, medicines and insects. One thing to particularly watch out for are house dust mites. If you don’t keep your apartment clean, then these dust mites can be life altering. The body thinks that this substance can be a threat, and therefore produce an inappropriate response, in the form of symptoms such as headaches and fatigue. What should you know? These symptoms often occur within a few minutes, but can also last up to two hours later.
Sensitivity
So, now you know what the symptoms are of a food allergy. However, you now need to learn what the symptoms are of a food sensitivity? Knowing the difference means you know how to treat it and you may not have to say goodbye to that hamburger forever, as you can help your body to cope. Why? This is because a sensitivity can simply be when you are having difficulty digesting certain foods, and you then experience those physical symptoms as a result of eating them. One big difference is that symptoms of a food sensitivity can emerge up to 72 hours later!

Remember:
Allergy = fast symptoms occurring almost immediately
Sensitivity = symptoms emerging up to 72 hours later

What is an allergy?

An allergy is a type I hypersensitivity which means exposure to an allergen results in the production of immunoglobulin E (IgE) antibodies, the release of histamine and symptoms. This is an immediate response, also known as an IgE-mediated immune response with symptoms occurring instantly, as soon the offending item is ingested, inhaled or touched. Symptoms do not always show up instantly and can occur up to two hours later.

Allergens are easy to identify due to the quick nature of the bodies reaction, however this does depend on the severity of the reaction as well as other factors such as hydration, time of year and even the processing level of a food.

Most people are aware that an allergic response to a food or non-food item has the potential be fatal in certain individuals. In the case of a severe allergy even the smallest traces of an allergen will have an effect on the body and will trigger a response within the immune system.

Depending on the type of item ingested and the individual, the symptoms can vary in how they show up. They can appear in the form of a rash, hives, vomiting immediately after ingesting food, wheezing, coughing, nausea and in severe cases the swelling of mouth, throat and tongue. Someone with multiple allergies may also have different symptoms to different items.

Upon seeing these symptoms present themselves it is incredibly important to know what to do next, as an allergic reaction has the potential to be very serious. If diagnosed with food allergies you must avoid all items that have been identified as triggers, especially if the allergy is severe or you suffer from asthma, so to avoid a potentially life-threatening situation. It is important to note that type I allergies are a lot less common than intolerances and sensitivities.

Why Do We Test IgG4 Over Total IgG Or IgG1?

Food allergies and sensitivities are becoming more and more talked about across a variety of sectors in the healthcare industry between both health professionals and their patients. Nutrition as a topic and, more specifically, allergies and sensitivities are getting more coverage than ever in mainstream media. This is helping spread vital awareness about potential symptoms and the benefits of testing.

IgG1 and IgG4

To test for immune-mediated sensitivities specifically, testing for IgG antibodies is required. Within the IgG class there are four IgG subclasses. There are a variety of IgG tests, which are available to health professionals worldwide, some testing all subclasses but there are on-going discussions about which is the most effective. Of the four subclasses the most commonly tested are IgG1 and IgG4, as these are produced in response to food antigens and can be used to identify sensitivities. IgG2 and IgG3 are not generally produced in response to food antigens. The main difference between IgG1 and IgG4 is how they respond to food antigens. IgG1 antibodies are like ‘first responders’ and are produced in response to new food antigens whereas IgG4 antibodies are produced when the body is continually exposed to an antigen. If you would like to learn more about the science behind the production of IgG1 and IgG4 antibodies click here.

Testing for IgG4 over IgG1 or total IgG has many pros, as it leads to a reduced number of false-positives and allows for more targeted, appropriate results. It reduces the incidence of patients unnecessarily removing too many foods, therefore improving patient compliance and outcome. To summarise, you are able to learn and understand the food items your body can tolerate, or, no longer tolerate and take steps to feel better and make important changes with confidence.

What is the difference between IgE & IgG4?

Our bodies main form of defence, the immune system, protects us from disease. Antibodies produced by the immune system are one method of protecting us from foreign bodies. They recognise and prevent bacteria and viruses from entering the body. The IgE class of these antibodies is responsible for allergic reactions. An IgE test from Lifelab will provide you with results on certain allergies.

If you think you may have an allergy you will need to take an IgE test. If you think you may have a sensitivity you will need an IgG4 test.

The IgG4 subclass is the least abundant type of antibody, and often needs building up. Sensitivity reactions are usually subtler than IgE symptoms – and include headaches, nausea, stomach cramps, diarrhoea or constipation, fatigue, skin disorders and lethargy – but can cause long-term damage and chronic discomfort. Lifelab IgG4 tests will provide you with results for a sensitivity.

What is the difference between IgE & IgG4?

Well, what is the difference? It’s a good question! Let’s start from the beginning. Our body’s defence system; the immune system, protects us from disease. Antibodies produced by the immune system are one method of protecting us from foreign bodies. This makes us feel better regarding our sensitivities and allergies! They recognize and prevent bacteria and viruses from entering the body. Moreover, the IgE class of these antibodies is responsible for allergic reactions. Lifelab IgE tests will provide you with results on certain allergies.

Knowing the difference

If you believe you have an allergy to certain food items then you will need to take an IgE test. Further, if you believe that you have a sensitivity, then you will need an IgG4 test. The IgG4 subclass is the least abundant type of antibody, and often needs building up. Sensitivity reactions are usually subtler than IgE symptoms – and include headaches, nausea, stomach cramps, diarrhoea or constipation, fatigue, skin disorders and lethargy – but can cause long-term damage and chronic discomfort. Lifelab IgG4 tests will provide you with the results for a sensitivity.

Understanding allergies

It’s important to know the difference between an allergy and sensitivity. The classification of allergic and hypersensitivity diseases, which were defined according to the European Academy of allergy and Clinical Immunology (EAACI) and the World Allergy Organization (WAO) is essential in providing a clarified definition.

According to the WAO, the correct diagnosis of an allergy is if specific conditions are met, including: a compatible clinical history, and positivity to in vivo and/or in vitro tests (IgE blood test or skin prick test) to prove underlying mechanism and etiology, meaning to be classified as allergic to an item there is a need for a positive test result as well as symptoms.

There are a variety of environmental influences and genetic factors of the host body, which underlie the immunopathogenesis of food allergy and its manifestations. There have been some clinical studies, which have altered many people’s understanding of what causes a food allergy. An example of this is the functional genetic variants in the IL-12 receptor b1, and the toll-like receptor 9, as these thymic stromal lymphopoietin genes and even IL-4 gene polymorphism have been associated with the increased risk of a hypersensitivity to certain foods.

Overall, food allergies are a chronic condition and can be hereditary. However, there has been a recent rise in women developing certain food allergies and allergic rhinitis during the menopause.

Allergies explained

In order for allergy to exist, allergen sensitisation must first occur. Antigen-presenting cells, including macrophages and dendritic cells are responsible for detecting the allergen. This can occur in a variety of ways, including inhalation into the nose and lungs, as well as through the skin and the gastrointestinal tract. When cells containing an antigen interact with an allergen, there is perceived to be an invader, even though this substance is not believed to be harmful on a normal basis. Subsequently, the allergen is then absorbed into the antigen-presenting cell, processed and then displayed on the surface of the cell.

What happens next is that the cell then migrates and presents the allergen, this process stimulates the B-cell, and produces antibodies specific to the allergen. From here, these specific antibodies, (IgE) are then released and are able to attach themselves to receptors on various surfaces of other cells in the mucosal surfaces and on subsequent basophils contained within the blood.

There is a period of sensitisation, and afterwards comes a period of latency, then on subsequent re-exposure to the allergen the allergic response is triggered. In this process an allergen is able to connect with the IgE on the surfaces of the mast cell, and this causes the cell to release nasty and inflammatory cell mediators. These include histamine and other mediators, all of which act differently and cause a variety of symptoms in different organs.

In order to fully define allergy pathogenesis and develop novel therapeutic possibilities, the key may well be in further understanding the gut microbiome and advancing research into epigenetics.

Prince, B.T; Mandel, M.J; Nadeau, K; Singh, A.M. Gut Microbiome and the Development of Food Allergy and Allergic Disease. Pediatric Clinics of North America. 2015;62:1479-92 Xie, J; Lotoski L.C; Chooniedass, R; et al. Elevated antigen-driven IL-9 responses are prominent in peanut allergic humans. PLoS One. 2012;7(10):e45377 Nursing Times. (2006). The pathophysiology of allergic responses.

Sian Baker DipION mBANT mCNHC

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Sian Baker DipION mBANT mCNHC

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