Food Allergy Flashcards
A 10-year-old boy presents to the clinic complaining of tongue and mouth itching within a few minutes after eating apples. His mother states that he has not experienced these symptoms with other foods, but they occur every time he eats a fresh apple. He denies systemic symptoms, and the oral symptoms resolve within a few minutes. Other than allergic rhinitis (nasal inflammation) in the spring months, he is healthy. Of the following, you are MOST likely to advise his mother that:
A) allergy skin testing to fresh apples probably will have negative results.
B) cooking the apple will not alter its allergenicity.
C) her son should avoid eating all fruits.
D) her son should avoid milk products.
E) her son’s symptoms are related to his allergic rhinitis.
E) her son’s symptoms are related to his allergic rhinitis
You are the ER physician and you give the child epinephrine injectable, followed by the antihistamine diphenhydramine (Benadryl), and some intravenous fluids. The mother asks you how she is supposed to know if the peanut caused the reaction or if it was something else and you tell her:
A. peanuts don’t cause allergic reactions if they are baked in a cookie.
B. who knows, she should have just given him diphenhydramine (Benadryl) and see if he okay.
C. this was a minor allergic reaction and she should just avoid peanuts in the future.
D. this was anaphylaxis, possibly to peanut, the epinephrine injection likely saved his life, but he needs further testing to find out for sure if it was peanut or another ingredient in the cookie.
D. this was anaphylaxis, possibly to peanut, the epinephrine injection likely saved his life, but he needs further testing to find out for sure if it was peanut or another ingredient in the cookie
What is sensitization?
May not go on to proceed to a clinical disease.
proven by IgE immunocap testing, skin testing, or oral challenge
Define a clinical food allergy. What differentiates it from sensization?
Sensitized
-Exposure causes reproducible characteristic IgE-mediated symptoms
(swelling, angioedema, hives, wheezing, histamine driven)
Compare intolerance to Allergy
Intolerance: your body cannot break down the food, if you eat small amounts you are okay, like with lactose causing pain, bloating, diarrhea with milk
Allergy: Your body mistakes that foord for something harmful leading to IgE-mediated reaction, there is an immmune reponse, and can be triggered by a microscoptic amount even by touch or inhalation or particles.
Is the presence of an atopic dz, like latex allergy, associated w/ a higher or lower prevalence of food allergy?
Higher
What are some of the most prevalent food allergies in children?
Cow’s milk, Egg, Peanut
What is the most prevalent food allergies in adults?
Crustaceans (Shellfish)
Differentiate the symptoms/complications of IgE medaited reaction vs. Non-IgE/Cemm mediated
In contrast to food intolerance, food allergy defines adverse reactions to food protein mediated by the immune system. Food allergy can be further divided into those allergies that are mediated by IgE antibody and those which are not IgE mediated. The IgE mediated food allergies are typically acute in onset and examples include anaphylaxis or urticaria. The non-IgE mediated food allergies are generally slower in onset and primarily are gastrointestinal reactions.
What some complications associated with IgE-mediated food allergies?
anaphylaxis, urticaria, angioedema, oral allergy syndrome, acute rhinitis, acute asthma
What is the typical chemical moiety of allergens? What are rarely allergens?
Proteins or glycoproteins (generally heat resistant and acid stable)
Rarely: carbohydrates
Describe the sensitization process on a molecular level (start with allergen and end with mast cell).
allergen -> allergen phagocytosed by DC -> allergen presented to allergen specific T cell -> Th2 -> Release IL-4, IL-5, IL-13 -> B cell stimulation -> Allergen specific IgE production -> IgE binds mast cell via Fc(epsilon)RI
What is released from mast cells during degranulation that causes the symptoms that present in IgE-mediated responses?
Histamines
Leukotrienes
Cytokines
Prostaglandins
PAF
What are some symptoms that people wrongly attribute to IgE-mediated food allergys?
Migraines, Behavioral / Developmental disorders, Arthritis, Seizures, Chronic fatigue, Inflammatory bowel disease
What do non-IgE medaited reactions primaryl manifest as?
Gastrointestinal symptoms like abdominal pain, vomiting, and diarrhea.
