September 21, 2015 - Food Allergy Flashcards
Angioedema
The rapid swelling (edema) of the dermis, subcutaneous tissue, mucosa, and sobmusocal tissues.
Basically the rapid swelling up of stuff… usually your face.
Atopic
A genetically based tendency to mount IgE responses to normally harmless airbourne and food antigens.
It is prevelant in approximately 30% of the population.
Mechanisms of Allergic Reactions
- Immunologic mechanisms (IgE-dependent)
- Immunologic mechanisms (IgE-independent)
- Nonimmunologic mechanisms (direct mast cell activation)
- Idiopathic
Serum Tryptase
Can indicate mast cell activation. You may order a serum tryptase to know if the patient was truly having an allergic reaction when you get the results back. It will not help for the time being.
Exposure at an Early Age and Allergy
Exposure to antigen (such as peanuts) at an early age shows a massive reduction in the number of children who become allergic to the substance.
Children who ate peanuts at an early age had an 86% relative reduction for developing allergies to peanuts than did the group that avoided peanuts.
P < 0.001
Therma Properties of Food
Some thermally unstable foods such as fruits and vegetables may cause an allergic reaction in their raw form, but be completely edible with no effects in their cooked form.
Other foods such as peanuts, are thermally stable and will trigger an allergic reaction whether cooked or not.
Allergy Skin Testing
The skin is rich in mast cells. The food antigen is placed onto the skin and pricked with a lancet. You also need negative and positive controls.
This has an excellent negative predictive value.
Exercise-Induced Anaphylaxis
Eating the food does not trigger the reaction, however exertion after eating the food does.
Exercise and heat are very important cofactors for allergy.
Risk Factors for Fatal Food Anaphylaxis
Asthma is huge.
Treatment for Anaphylaxis
Epinephrine.
Patients with known food allergies should not be on beta-blockers as this will render the epinephrine useless.
