The BSACI is an organisation for professionals working in allergy. Its mission is to improve patient care through education, training and research. Patients may find the following brief explanations about allergy and allergic diseases helpful.
Allergy is a type of hypersensitivity reaction in which the immune system produces IgE antibodies against harmless antigens such as grass pollen. The antigens that provoke the allergic over-reactions are called allergens. The IgE reaction with allergen results in the release of powerful chemicals, including histamine from mast cells and local or general inflammation. Allergy in medical terms means that the person develops symptoms upon contact with allergens to which he/she is sensitised.
Many allergens can trigger an allergic response. The immune reaction is essentially the same to all of them but the resulting allergic diseases can be diverse: symptoms can vary: e.g. sneezing, wheezing, itching, rashes, can be manifest in different organs:nose, skin, lungs, eyes with varying degrees of severity.
Atopy is the genetic predisposition of an individual to produce high quantities of IgE in response to allergens in the environment (pollens, house dust mites, moulds, cat dander, foods etc). Heredity is important in atopy: the predisposition to produce IgE is inherited from your mother, your father, or both. However a child without allergic parents still has a 15% chance of becoming allergic, if the mother is allergic the risk is 60% and if both parents are allergic the risk is 80%.
Sensitisation means that the immune system has recognized and memorized an allergen and has synthesised IgE antibodies to it. The time taken to become sensitized to an allergen varies from days to years and occurs silently. Some people stop in this phase and never develop allergy symptoms even if exposed heavily and for long term to allergens to which they bear IgE antibodies. Such individuals have positive allergy tests without evident allergic disease and therefore are considered to be healthy but with a higher risk for developing allergy than non sensitized individuals.
The fact that positive IgE tests occur in individuals without clinical disease means that such tests should never be done in isolation but only as part of a consultation with someone properly trained in allergy.
Pseudo-allergies: In addition to allergic diseases there are so called pseudo-allergies in which mast cell degranulation occurs by mechanisms other than IgE. These maladies have similar symptoms to allergies (i.e. skin rash, itching, sneezing, runny nose, coughing, wheezing, etc.). The difference is that because they are not caused by IgE, skin prick and blood tests are not helpful in diagnosis.
As an organisation the BSACI does not recommend allergy testing for IgE at a distance or by untrained individuals and would not advise the use of unproven tests such as kinesiology, Vega tests, hair analysis, IgG to foods, etc.
"Making Sense of Allergies is a public guide that investigates ideas about the causes, diagnosis and treatment of allergies with a group of allergy specialists and has brought together points to help you make sense of it all."
If you would like to read the full publication please click here.
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