Delayed Onset
(IgG-Mediated)
|
Immediate Onset
(IgE-Mediated)
|
| Multiple foods
can be involved |
Rarely more
than 1-2 foods
involved. |
| Large amount
of the food needed to provoke symptoms; reactions may not occur after
single food challenge. |
Even trace
amounts of food
can trigger severe life threatening reactions. |
| Reactions
occur 2-24 hours after eating reactive foods; rarely up to 72 hours
have reactions been reported. |
Reactions
occur 2 hours or
less after consumption of offending foods. |
| Any organ
system can be involved in reaction including the classic allergic
areas. |
Primarily
affects: Skin, airway, and digestive system. Classic processes: hives,
asthma, eczema, vomiting, diarrhea, and anaphylaxis. |
| Very common
(children, and adults) Over 50 medical problems caused, provoked or
worsened by food sensitivities. |
Rare in
adults. |
| Addictive
cravings and withdrawal seen in 20-30%. |
Addictive
cravings never seen. |
| Because
multiple foods and delayed onset of symptoms, the offending foods
rarely self-diagnosed. |
Offending food
is often diagnosed because of immediate reaction. |
| Allergic foods
are favorite
foods. |
Allergic food
is a rarely eaten food. |
| Symptoms clear
after avoidance for 6 months. |
A permanent
fixed allergy. |
| IgE RAST
negative; IgG positive (type II) often. |
IgE and skin
test positive
(type I) reaction. |
| IgG food
immune complexes (type E) and cellular (type IV) reactions common. |
IgG not
involved. |
| Sensitized
lymphocytes, eosinophils, platelets, release of leukotrienes
prevalent. |
Mast cell
release of histamine and tryptase involved. |