Allergy Explained in Human Language

Allergy Explained in Human Language
Child Health and Nutrition

Have you noticed that there’s quite a lot of children with food allergies wherever you go? There has never been so many people suffering from food, pollen or any other kind of allergy before. It’s sad as it affects everyday life of individuals and entire families. On the other hand, awareness is rising and life with food allergy is becoming better manageable. If you’re one of the “sufferers” you will get more support and understanding of your condition. It will certainly make your life easier and more enjoyable every step of the way.

What is an allergy?

Once upon a time there was an Immune System…

Immune system is very useful and important. It comes across hundreds of substances everyday, identifies enemies (pathogens) and fights them in a very effective way. Sometimes, or better to say: in some people, the immune system gets confused and mistakes harmless substances for an enemy. It acts like if tiny particles of pollen (or anything you’re allergic to) were a dangerous aggressors which are about to cause major disease if not destructed right away.

Allergy and it’s most common symptoms

Depending on how bad your allergy is and what is its cause, you might experience mild, intermediate or severe symptoms. The most common symptoms are:

  • Hives (skin rash)
  • Runny nose
  • Swelling of your skin or mucosa in your mouth or nose
  • Headache
  • Sneezing
  • Digestive problems such as nausea or diarrhoea
  • Anaphylaxis (can be life-threatening)

If your symptoms kick in immediately after the contact with allergen, it is most likely an IgE mediated allergy (explained below) what you have. It’s also much easier to determine what’s causing it. On the other hand, if you’re suffering from some symptoms and don’t know why, it takes much more time and effort to get the right diagnosis and treatment.

In all cases, the best way how to avoid symptoms is avoiding the allergen. Easy right? Well… first of all, you need to know WHAT to avoid (what are you allergic to), WHERE it is and you should also know what to do in case you do come in contact with the allergen.

Types of allergy

In general there are two types of allergies:

  • IgE mediated – causes immediate reaction which can differ depending on how severe your allergy is and which part of your body is affected.
  • non-IgE mediated – usually causes slow reaction starting few hours after encountering the allergen. It’s much more difficult to determine what’s causing the symptoms and to confirm that it is, in fact, an allergy what you have.

IgE mediated allergy

Let’s find out more about IgE mediated allergy, as it is better known, affects many people and can cause very severe symptoms.

As your body “decides” that certain harmless thing (allergen) is its enemy, your immune system wants to identify it as soon as possible after coming in contact with it. First step is to create antibodies against the enemy. It creates specific antibodies called IgE (immunoglobulin E) and sends them to guard and attack the enemies right at the front door to your body. How? Certain white blood cells called Mast Cells bend with IgE (get IgE sensitised). This means that they get an information that the allergen is enemy and needs to be liquidated. Mast cells with this information are waiting in your nose, mouth, in your skin etc. and when they get in touch with the allergen, they burst and release histamine (along with the other chemicals). This leads to the symptoms you’re experiencing during your allergic reaction.

Don’t blame mast cells

Mast cells are causing trouble only if you’re allergic to something. Besides causing an allergic reaction, they’re playing important role in protecting you from some pathogens that could make you really sick. They identify the enemy, attack, sometimes even kill the enemy and also inform the rest of your body about the thread. Mast cells become the source of struggle only if they’re IgE sensitised against allergen, that is, in fact, not dangerous for your body at all. Normal level of IgE of non-allergic person is below 0.05% of the Ig concentration.

Allergy testing

If you suspect allergy in your child (or yourself), your family doctor should refer you to an immuno-allergology specialist who will perform allergy testing. There are two types of testing: Skin tests and blood tests. Depending on age, previous reactions to allergens and other circumstances, doctor will recommend you one or sometimes even both methods of testing to be performed.

1. Blood test for allergy

There’s no age limit for blood tests, so if your child is little, this is the best way of testing. Blood sample will be taken and sent to the laboratory. The sample will be checked if it contains specific IgE antibodies against certain allergens (number of different allergens tested in each blood sample might be limited). If it does, they will be displayed as IgE in kU/l on your blood test results. Measurement units kU/l means one thousand units (of IgE) per litre of serum (abstract of the blood sample). Depending on how high is IgE concentration, your results will be interpreted.

Reference Values for IgE testing

ClassIgE kU/LInterpretation
0<0.35Negative
10.35-0.69Equivocal
20.70-3.49Positive
33.50-17.4Positive
417.5-49.9Strongly positive
550.0-99.9Strongly positive
6> or =100Strongly positive

Reference values apply to all ages. Source: https://www.mayomedicallaboratories.com

2. Skin test for allergy

If your doctor decides to do the skin test, they will do a prick into your skin with a tiny drop of liquid containing the allergen. Than you will be asked to wait for few minutes before the results will be read. It’s simple. If your skin becomes irritated and the hives appear in the spot of a prick, you’re clearly experiencing an allergic reaction. Depending on how big the hives are and how fast they appear, the doctor will mark the results on the scale. It is very important that you’re not taking any medication that can interfere with the results at the time of taking skin prick test for allergy. Always inform your doctor if you’re taking anything and also make sure you follow all the instructions you get before performing the test. Usually you need to leave out certain medicines for several days before the testing.

Skin prick test for allergy interpretation

Wheal size (mm)Old “+” scaleInterpretation
<40+Negative
5 – 102+Mildly sensitive
10 – 153+Moderately sensitive
>154+Very sensitive

Source: http://www.dermnetnz.org/topics/skin-prick-testing/

No matter if you get a skin test or blood test done, even though these are the exact methods for allergy determination, the results must be interpreted very individually. In the bigger picture of your symptoms and medical history. Your doctor will go through your options and suggest the treatment. You will learn what to do in case of allergic reaction and get some medications to control your allergy. The whole point of it all is for you (or your child) to live normal, full, enjoyable life without suffering or worry. Allergy is not the end of the world and it certainly isn’t any huge, horrific disease. Every human body is different and therefore different things are helping it to thrive. No matter if you do have allergy or not, you should listen to your body and do things and eat things that will keep you healthy and happy. I wish the very best of luck and you can look forward to more articles about life with allergy.

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Sources:
http://www.eaaci.org/
http://www.allergyuk.org/what-is-an-allergy/what-is-an-allergy?cookieaccept=true
https://en.wikipedia.org/wiki/Mast_cell
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3343118/
http://www.kidswithfoodallergies.org/page/what-is-a-food-allergy.aspx
https://en.wikipedia.org/wiki/Immunoglobulin_E
https://myhealth.alberta.ca/health/pages/conditions.aspx?hwid=stu3135&

 

About Jarmila

I’m a mom of three (8, 6, 4). For me, having kids means my biggest dream coming true. It’s blessing from God to have them. Although, it still applies, that children are best when they’re asleep. And on photos, too. Every night when they’re all 3 fast asleep, I go to check on them and I watch them with a smile on my face. Their breath is calm and their little faces are so beautiful and gentle. I think of all the funny things they’ve said and done that day. Or even naughty little things they’ve done. I just smile and enjoy the moment and the quiet in the house :)