What is Allergy? Am I Allergical?
What is Allergy?
Words matter, particularly in medicine. Using the same words to mean different things is a major difficulty for patients when discussing allergies with a doctor. Unfortunately, few patients realise this, and doctors are frequently too busy to explain what they themselves mean. The result can be a great deal of misunderstanding, confusion and mutual irritation.
Unclear meanings can also create problems if you start exploring other treatment options. The word `allergy’ is like one of those cats that eat at six different houses in the neighbourhood: everyone feels as if they own it exclusively. A conventional allergist will understand one thing by ‘allergy’, while a more unorthodox doctor may have a broader definition, and a herbalist or naturopath may be using the word in a completely different way again.
This is an absolute jungle for the medically unqualified, and it can be an expensive jungle if you are looking around for an answer to your health problems. With the help of this book, you should be able to make sense of all this, and understand the seemingly contradictory advice on offer.
The word allergy was coined in 1906 when it was used to mean altered reactivity - any change in the way the body responds to the environment, whether immunity to a disease already encountered, or a sudden fit of sneezing from pollen. Immunity to disease was soon shunted off into a separate category
altogether, leaving allergy with a narrower meaning:
any adverse reaction to substances that are normally harmless - definition 1. In this book, that meaning is covered by the word sensitivity.
One group of American doctors, who later became known as clinical ecologists, stuck with this definition. Their broad view of allergy is still found among some other doctors today, generally those whose approach to medicine is fairly unorthodox. It is a concept of allergy that is also shared by most practitioners of alternative medicine or complementary therapists.
The rift between the clinical ecologists and mainstream medicine came in the 1920s when the definition of allergy used by conventional doctors was narrowed further to mean reactions to harmless items where the immune system is definitely involved -definition 2. The term immune sensitivity is used in this book to convey that meaning.
In the 1960s, conventional allergists narrowed the definition of allergy again. It was an exciting time because the antibody known as IgE (sometimes called the allergy antibody - see box on p. 12) had just been discovered. The new, tighter meaning of allergy was
reactions to harmless items where IgE is involved -definition 3.
If asked to define allergy, most doctors would give the second of these definitions.
However, when they talk of ‘a tendency to allergy’, ‘allergy treatment’ or `the allergy epidemic’, doctors are generally using the third definition, and just mean IgE-mediated allergy. They may not be conscious of the fact that they are switching from one definition to another. This is not an ideal situation but, generally speaking, it does not create too many problems.
This book deals with ‘allergy’ in the very broadest sense of the word - all kinds of sensitivity. However -and this is purely for the purposes of clarity - where the word allergy is used in the text it always means IgE-mediated allergy (definition 3).
Other immune-mediated problems are called non-IgE immune sensitivity in this book.
Finally, any reaction where the immune system has no proven central role is called an intolerance. (As for other technical words, if you want to find the full definition, look in the index and turn to the page number shown in bold type.)
If you are reading widely on this topic, you may come across sensitivity used either according to definition 1 above, or as another name for intolerance. You may also encounter the word hypersensitivity. This is actually a precise medical term,
but be warned that some writers use ‘hypersensitivity’ very loosely to mean just ’sensitivity’ (definition 1).
Remember that medical politics and economics are powerful forces in all this debate over meanings. Words are quite often redefined by medical interest
groups (such as professional associations) with the clear intention of staking out territory and claiming sole access to medical truth. What is at stake, ultimately, is the right of different doctors to treat patients with certain conditions - and the right of patients to choose for themselves. To add to the longstanding battle over ‘allergy’, there are now rival claims about the meaning of intolerance (74) which have distinctly political overtones.
When you talk with doctors, using the most appropriate terms will help enormously. Talking to a mainstream doctor about ‘food allergy’ when the symptoms suggest food intolerance, for example, is very likely to cause annoyance. This is not unreasonable because IgE-mediated food allergy, unlike food intolerance, is a disease that can very suddenly kill an otherwise healthy person. Using the term `food allergy’ for a headache or mild bowel symptoms is, doctors feel, trivialising a potentially fatal condition.
The important thing is to get along well and communicate clearly with doctors, not to get into a battle about what words mean (in that sense, words don’t matter - they are just labels). Avoid using the word ‘allergy’ unless you are sure it fits in with your doctor’s perception of what is wrong. Just describing how you react - the actual symptoms - is usually the best approach. If you need a general word for your condition, ’sensitive’ is usually a much more diplomatic choice than ‘allergic’.