Immediate and Delayed Food Allergy (IgE, IgG)
The foods we eat have changed significantly
over the past 100 years. Modern diets contain greater numbers of spices and
exotic foods, increasing numbers of preservatives and additives, and foods that
have been modified by elaborate processing techniques.
Concurrent with these changes in diet, there
has been an increase in the incidence of eczema, irritable bowel syndrome,
migraine headaches, hives, rhinitis, asthma, arthritis, and general aches and
pains. Allergies have been shown to play a role in these conditions. It has
been suggested that food allergies, brought on by increasingly diverse and
immunogenic (immune system activating) diets, may be responsible for many of
the chronic complaints that are seen today.
Reactions to foods can occur immediately (Type I
hypersensitivity) or up to a few days later (Type III hypersensitivity). Type I
hypersensitivity is usually associated with IgE production, which stimulates
the release of histamines, among other chemical messengers.
hypersensitivity is mediated by IgG production. Food-specific IgG’s attach to
food allergens, forming immune complexes; if not cleared by the body, these
complexes can deposit at various sites in the body, where they become a source of
inflammation or other irritation. Most laboratories performing food allergy
tests identify the presence of IgE- and IgG-type antibodies. Foods that
stimulate elevated IgE responses are responsible for some of the most serious
clinical problems and should be avoided completely, whereas foods that
stimulate IgG production may be eliminated temporarily in order to evaluate
patient response. Although IgE is normally associated with the allergic
response, it has been suggested that up to 90% of food allergies are
IgG-mediated. For this reason, it is important to test for the presence of both
of these antibody types.
Consider IgG testing for patients with chronic
conditions involving any system –
Gastrointestinal (distension, bloating,
cramping, colic, N/V, diarrhea)
Respiratory allergic reactions (rhinitis, nasal
Dermal (ECZEMA, angioedema)
CNS (mood, behavior,
learning difficulties, H/A)
Neurovascular (migraines, Meniere’s)
Musculoskelatal (weakness, feeling “below par”, arthralgia, myalgia).