Thursday 28 June 2012

Talk : Allergy

The Nottingham Branch of the British Science Association, in collaboration wtih the University of Nottingham, recently held a talk entitled "Myths, media, medicine and madness – tackling ignorance about allergy an hour at a time".

This talk, presented by consultant paediatrician Dr Will Carroll, aimed to tackle a few myths that plague the field of allergy, and highlight how the science behind allergy is actually quite well known.

NSB unfortunately missed the talk, but Dr Will Carroll was kind enough to supply a summary by email, which is what this post is based on.

It’s perhaps worth just outlining what an allergy Is - and the NHS has a usefully clear explanation:



An allergy develops when the body’s immune system reacts to an allergen as though it is a threat, like an infection. It produces antibodies to fight off the allergen, in a reaction called the immune response.

The next time a person comes into contact with the allergen, the body "remembers" the previous exposure and produces more of the antibodies. This causes the release of chemicals in the body that lead to an allergic reaction.

SEM  images of Pollen from typical garden flowers

The internet remains a dangerous source of information for parents; yet is an excellent source of material for a talk about myths in the field of allergy. There really is some nonsense out there! Some of which looks and sounds plausible but has the potential for great harm.

Dr Carroll presented a few examples of such pseudoscientific treatments, including hair testing, vega testing, kinesiology and the York test (see also this article) - and then went on to point out how the media perpetuated the lack of understanding in this field .

One surprising point that Dr Carroll made was that there are about three times as many people who have an “allergic sensitisation” than are truly “allergic”.

To explain this a bit further, people who have an allergic sensitisation produce antibodies to combat certain foods or other stimulus - but DO NOT have any clinical reactions. This is to say, these people essentially do not know they are sensitized, and suffer no ill effects such as rashes etc - possibly because other 'good' antibodies block allergic type reactions. This is what happens when children 'outgrow' milk and egg allergy.

All of this shows just how complicated the interpretation of test results can be and that testing really does need to be performed by a clinician with allergy training.

Histamine

Note : Dr Carroll is also involved in the Midlands Asthma and Allergy Research Association (www.maara.org) -check it out, there is some interesting stuff there !

Image Sources : Pollen, Histamine

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