7/27/2019 Allergology RR

1/2

ALLERGOLOGY Removals Review

By Alec Maquiling

OUTLINE

I. Adverse Food ReactionsII. AnaphylaxisIII. Urticaria and Angioedema

I. ADVERSE FOOD REACTIONS

Definition: ANY reaction following theingestion of a food.

A. ORAL FOOD TOLERANCE: suppression of

adverse immune responses to nonharmful food

antigens.

A1. Mechanisms:

1. Mucosal Barrier (Intestinal Intraepithelial

cells, secretory IgA, Regulatory T cells,

Commensal Flora)

2. Balance of Th1 and Th2 cells

B. FOOD INTOLERANCE: adverse event

WITHOUT a clear immune mechanism

B1. HOST factors: enzyme deficiencies, GI

disorders, idiosyncratic reaction, psychologic,

migraines

B2. FOOD factors: infectious organisms (S.

aureus, E. coli, C. difficile), toxins (scombroid

poisoning [histamine]), pharmacologic agents,

contaminants

C. FOOD ALLERGY (FA): a reaction WITH an

immune mechanism

C1. Prevalence

- 2.5% of newborn infants have hypersensitivity

to COW MILK in the FIRST year of life.

-About 1.5% of young children are allergic to

EGGS.

C2. Common food allergens (in the Philippines)

- Seafood, fish, eff, milk, soy, peanuts (Note:

Chicken allergy is NOT common)

- PEANUT allergy: most common cause ofanaphylaxis in children leading to an ER

consultation.

- REMEMBER: PROTEIN component is

responsible for causing food allergy

C3. Genetics (chance of getting food allergy)

- If both parents both have food allergy: 50-80%

- If both parents are atopic: 40-60%

- If one of the parents have food allergy: 40%

- If neither parent has food allergy: 15%

C4. Cross-reactivity: when an antibody reacts

not only with the original allergen but also with

a similar allergen

-NOTE: LATEX cross reacts with banana,

avocado, kiwi, and chestnuts

C5. Correlation with other diseases- FA coexists with asthma, atopic dermatitis,

eosinophilic esophagitis, and exercise-induced

anaphylaxis

-Coexistence of FA and ASTHMA is a risk factor

for asthma exacerbations

- Exercise-induced anaphylaxis: it happens

when you eat a certain food (most common

triggers: shellfish, alcohol, tomatoes, cheese,

celery), then you exercise. The food triggers

mentioned can be eaten WITHOUT symptoms in

the absence of exercise.

- 75% of patients who experience this

are females!

C6. Natural History of Food Allergy

- Most FA will tolerate milk, egg, soy and wheat

(but time course varies and may occur as late as

teenage years)

- A higher initial level of serum IgE against a

certain food is associated with a lower rate of

resolution

C7. Types of Food Allergy (REMEMBER THIS)

C7.1 IgE-MEDIATED FOOD ALLERGY

C7.1.1 Clinical Features:

-RAPID onset (within 1-2 hours)

-Resolve quickly (within minutes to few

hours)

-Several symptoms involved: MOST

COMMONLY INVOLVED: SKIN, 2nd most

commonly involved: Gastrointestinal

C7.1.2 Examples of IgE-Mediated Food

Allergy

1. Oral Allergy Syndrome-aka POLLEN-associated FA syndrome (because

it also commonly affects those who are allergic

to pollens)

-allergy usually to RAW fruits and vegetables

- confined to LIPS, MOUTH, THROAT

2. Acute Urticaria

- rapid onset after ingestion of food

characterized by round or irregular shaped

PRURITIC WHEALS

7/27/2019 Allergology RR

2/2

ALLERGOLOGY Removals Review

By Alec Maquiling

3. Angioedema

-often occurs in combination with urticaria

-NON-pitting, NON-pruritic, well-defined

edematous swelling that involves subcutaneous,

abdominal organs or upper airway.

C7.1.3 Examples of Non-IgE-Mediated FoodAllergy

1. Food Protein-Induced Allergic

Proctocolitis

-in healthy infants who have visible specks or

streaks of blood with mucus in the stool

-many infants present while being breast-fed

2. Food Protein-Induced Enterocolitis

Syndrome

- presents as chronic emesis, diarrhea, failure to

thrive

- in young people, most common cause are milk

and soy protein

-in adults, most often related crustacean

shellfish ingestion.

C7.1.4 Mixed Conditions (both IgE and Non-

IgE-mediated)

1. Eosinophilic Esophagitis

- LOCALIZED inflammation of the esophagus

2. Esophageal Gastroenteritis

-pathologic infiltration of the GI tract byeosinophils

3. Atopic Dermatitis

- skin barrier dysfunction

- mutation on the protein FILAGGRIN

- Atopic March (Atopic Dermatitis then Asthma

then Allergic Rhinitis)

C8. Diagnosis of Food Allergy

-FA should be considered in patients with

anaphylaxis or any combination of symptoms

that occur within minutes to hours of ingesting

food.- Although History and PE can aid in the

diagnosis, they CANNOT be considered

diagnostic of FA. Moreover, parent and patient

reports must be CONFIRMED because 50 to 90%

of presumed FAs are not allergies.

- IgE-mediated Skin Prick Test: cannot be

diagnostic BUT can be used to confirm ABSENCE

of IgE-mediated reaction

- Double Blind Placebo Controlled Oral Food

Challenge (Gold Standard)

C9. Management of Food Allergy

- currently NO CURE exists

- standard of care: STRICT ALLERGEN

AVOIDANCE

-NOTE: VERY IMPORTANT to memorize Labels

that Indicate Egg Protein (particularly ALBUMIN,binder, coagulant, egg white, egg yolk, emulsifier,

globulin, lecithin, livetin, lysozyme, OVALBUMIN,

OVAMUCIN, OVOVITELLIN, powdered egg,

vitellin, whole egg) and food that may contain

egg protein (baked goods, baking mixes,

boullion, breakfast cereals, cake flours, candy,

cookies, egg noodles, French toast, ice cream,

macaroni, cocoa, marshmallows, MEATBALLS,

SAUSAGES,