For people with severe allergic reactions, such as deadly peanut allergies, there is no safe amount of an allergen. But for most people, allergies have a safety threshold. This threshold level affects how much of an allergen they can be exposed to before reacting and how likely they are to react to other allergens, from food allergies to reactions to dust, mold, chemicals, perfume, detergents, and more.
The allergy threshold is the amount of an allergen a person can be exposed to before he begins to react to it.
The threshold may also be the cause of certain allergies, particularly in childhood, when the immune system is more sensitive. Children who eat the same foods every day – foods like milk, wheat flour, and sugar, three of the most common food allergies – may develop an allergy to some or all forms of that food.
An allergy threshold is generally reached through repeated exposure to a particular allergen. Someone who lives in a dusty house, for instance, may develop a dust allergy. A woman living with several cats that shed voluminously may become allergic to cat dander or to animal dander in general.
Food allergies can also be created by repeated exposure, as mentioned above. Some holistic diets recommend rotating the foods eaten, so that allergies don't develop.
Many of the synthetic chemicals present in hairspray, perfume, cosmetics, antiperspirants, and other beauty and personal care products are toxic to the human body to a certain extent: they won't kill you immediately, but are potentially carcinogenic and immune suppressive.
Because allergies are, basically, a misfiring of the immune system's response to threat, anything that interacts with the immune system in a less-than-beneficial way worsens the chances that an allergy will go by without a reaction. Daily exposure to synthetic chemicals in laundry detergent, other cleaning products, perfume, hairspray, and more consistently worsen allergic reactions.
Unfortunately, allergy thresholds tend to connect allergies that might not otherwise be connected. Daily exposure to animals, for instance, can lead to increased reactivity to dust, perfume, or foods; and food sensitivities can worsen in the spring and fall, when there is more mold and pollen in the air outside.
Once an allergy threshold is reached, things can get messy. Children with allergies or sensitivities often seem to react to "anything and everything" because their immune system is so overloaded by allergens like wheat, nuts, dairy, perfume, mold or pollen that everything else becomes a problem too.
It's a good idea to minimize any exposure to known allergens or sensitivities, but this can be difficult at times. The following recommendations can help keep a safe margin between your immune system and an allergic reaction: