THE MOST COMMON CAUSES OF ALLERGY
Inhalants
Allergy to inhalants, particles you can inhale, is usually clearly identified by skin and blood tests. The IgE mechanism appears to be principally responsible for such reactions.
Foods
Food allergy is perhaps less common than most people believe, since many cases of reaction to foods are food intolerance, rather than true allergy. Allergy to foods, rather than intolerance, will show positive results to skin and blood tests. You are likely to react whenever you eat a food to which you are allergic, even if you have not eaten it for a very long time; and you are more likely to have an immediate reaction, even to a small or tiny amount of the food. You may also be able to remember a precise date or occasion when you first reacted to a food. Food intolerance has a different pattern of reaction, and different symptoms (see page 20).
Table 1: The Most Common Causes of Allergy
INHALANTS
House dust mites
Animal and pet hair
Mould spores
Pollens
Feathers
Wools
Dusts at work
FOODS
Cow’s milk, butter, cheese, yogurt
Eggs
Wheat
Yeast
Oranges, lemons, grapefruit, satsumas
Nuts
Beans, pulses, soya products
CHEMICALS
Formaldehyde
Perfumes and fragrances
Paraphenylenediamine (PPDA)
Rubber
Phenols and cresols
METALS
Nickel
Chromates
Chemicals and metals
Allergy to chemicals and metals is sometimes very hard to distinguish from chemical sensitivity. In allergic contact dermatitis, where reactions are often delayed, positive results from patch tests on skin can often establish that an allergic reaction is involved. However, in many cases of asthma, eczema and dermatitis, tests are inconclusive and the dividing line between allergy and sensitivity is unclear.
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Tags: Allergies