Allergies

Question 1

Type 1 Allergic Reaction

Answer 1

Type 1 reactions involve the interaction between an antigen and a specific immunoglobulin (Ig) E antibody.

Question 2

Type 2 Allergic Reactions

Answer 2

Type II reactions, also known as cytotoxic reactions, occur when an antibody reacts with an antigenic component of a cell.

Question 3

Type 3 Allergic Reactions

Answer 3

Type III reactions result from immune complexes that activate the complement system.

Question 4

Type 4 Allergic Reactions

Answer 4

Type IV reactions are also called delayed hypersensitivity reactions. These cell-mediated reactions are the result of sensitized T lymphocytes coming into contact with a specific antigen.

Question 5

Treatment for Allergic Reactions
(Not anaphylactic)

Answer 5

Remove allergen
Antihistamines and corticosteroids

Question 6

How to Antihistamines work

Answer 6

They block the action of histamines at the receptor site
H1 blocks smooth muscle
H2 blocks gastric acid response

Question 7

First generation antihistamine

Answer 7

Act centrally

diphenhydramine
hydroxyzine
chlorpheniramine
These agents are typically very effective, but they may also be very sedating. Cross the blood/brain barrier and cause CNS effects

Question 8

Second generation antihistamines

Answer 8

Act Peripherally
Loratadine and fexofenadine are nonsedating antihistamines (NSAs) that work well at controlling mild to moderate symptoms of cutaneous reactions.

Question 9

What is Anaphylaxis

Answer 9

Anaphylaxis is a type I hypersensitivity reaction (quick, 1-30 minutes onset)
IgE mediated
Symptoms such as angioedema, flushing, pruritus, urticaria, nausea, vomiting, and wheezing due to smooth muscle contractions. Can lead to shock b/c fluids are displaced (vasodilation)

Question 10

What is are anaphylactoid reactions

Answer 10

Anaphylactoid reactions are similar in appearance to anaphylaxis but may occur after the first injection of certain drugs and contrast media. Ex: Red man syndrome with Vancomycin.
Non-IgE mediated
Itching, redness, hives after rapid infusion

Question 11

Treatment of Anaphylaxis and Anaphylactoid Reactions

Answer 11

Immediate treatment with epinephrine 0.01 mL/kg aqueous epinephrine 1:1,000 (1 mg/mL) subcutaneously or intramuscularly in lateral thigh should be given. Every 5-15 minutes
Benadryl IM helpful but these do not treat airway obstruction, hypotension, or shock.

Question 12

Allergic Rhinitis Drug Therapy

Answer 12

Antihistamine, nasal decongestant, intranasal corticosteroids

Question 13

2nd generation Antihistamine drugs

Answer 13

Cetirizine (Zyrtec): 5-10mg
Levocetirizine (Xyzal): 2.5-5mg
Fexofenadine (Allegra): 60mg
Loratadine (Claritin): 10mg
Desloratadine (Clarinex): 5mg

Question 14

Intranasal Antihistamines

Answer 14

Olopatadine (Patanase)
Azelastine (astepro)
Dymista
Side-effects: bitter taste, dryness, nosebleeds, nasal ulcer, headache

Question 15

IntraNasal Decongestants

Answer 15

Oxymetazoline (afrin)
Phenylephrine (neo-synephrine)
Tetrahydrozolone (Tyzine)
Xylometazine (Triaminic Decongestant)

Question 16

Intra-nasal Cromolyn

Answer 16

Mast Cell Stabilizer
It is used only for prevention.
Begin 2-4 weeks before season

Question 17

Intra-nasal Corticosteroid
“Sones” and “ides”

Answer 17

Max effect not seen until 1-2 weeks.
Initiate 2-4 weeks before season.
Side effects: local irritation, bleeding
Fluticasone (Flonase)
Beclomethasone
Budesonideciclesonide
flunisolide
Mometasone
Triamcinolone

Question 18

Allergic Conjunctivitis

Answer 18

Mast cells abundant in the eyelid and conjunctiva
Tx (non-pharmacologic): cool compresses to eyelids, artificial tears-wash away allergens
Always educate to remove triggers from home, if possible
Tx (pharmacologic): antihistamines, vasoconstrictor/antihistamine combination, mast-cell stabilizers, NSAIDS