WK2 - Lecture 10 - Allergic Reaction.pdf

DH 410 EMERGENCIES IN DENTAL PRACTICE Lecture 10: Allergic Reactions Objectives  Discuss the pathophysiology of an allergic reaction  Compare and contrast specific signs and symptoms associated with mild, moderate, and severe allergic reactions  Understand and determin...

DH 410 EMERGENCIES IN DENTAL PRACTICE Lecture 10: Allergic Reactions Objectives  Discuss the pathophysiology of an allergic reaction  Compare and contrast specific signs and symptoms associated with mild, moderate, and severe allergic reactions  Understand and determine suggested treatment modalities for different types of allergic reactions  Explain steps needed to prepare for a patient experiencing an allergic response THINK OF ONE ALLERGEN YOU MAY HAVE…  WHAT WAS YOUR REACTION?  HOW WAS IT MANAGED?  DO YOU HAVE AN EpiPen? Allergy  Hypersensitivity to an ordinarily harmless substance  State of abnormal sensitivity by being exposed to a particular allergen  Most common are environmental Allergy Etiologies:  Dust  Pollen  Latex  Insect stings  Foods  peanuts, tree nuts, shellfish, milk, eggs, wheat,  Medications  aspirin, NSAIDS, penicillin, etc…  Allergy  Reaction varies from mild symptoms to life-threatening  MILD  rash, sneezing, watery eyes, runny nose, skin irritation  SEVERE  hypotension, dyspnea (difficulty breathing), life-threatening  ANAPHYKAXIS  The quicker the reaction occurs, the more life-threatening  Severity often dependent upon:  Amount of allergen  Rate of exposure  Route of exposure  Allergy  Severity often dependent upon:  Amount of allergen  Rate of exposure  Route of exposure Quicker the reaction = more life threatening Allergy  Affects 10-30% of USA population  1,500 deaths per year in United States due to allergy  Death more likely in older individuals and females  via cardiovascular collapse and respiratory arrest  Estrogen may play a role in women https://www.washingtonpost.com/news/to-your-health/wp/2014/12/29/why-women-may-have-more- serious-allergic-reactions-than-men-do/?noredirect=on&utm_term=.aae75a37e307  Allergy: Physiologic Response 1st Exposure to antigen  “sensitizing dose”  Production of antibodies to fight off antigen  Triggers IgE antibodies to become bound to mast cells  Antigen becomes allergen  Lies dormant until body encounters antigen again  Allergy 2nd Subsequent dose of allergen  “challenge dose”  Histamine released causing a reaction  Chemical mediators found in lungs, small intestine, and connective tissue spill from the cell and attack allergen  ALLERGIC REACTION Allergic rhinitis  Signs and Symptoms: Allergy  Variable  Tend to develop gradually  More severe = quicker response  Generally begin with  pruritus (sever itching) - throat, palms or soles of feet  urticaria (hives)  angioedema (swelling)  Others (like insect stings) trend with cardiovascular, respiratory, or GI symptoms  Not all signs and symptoms present simultaneously  Some may not present at all  Reactions are specific and unique to that individual  Signs and Symptoms: Allergy MILD to MODERATE  Urticaria (hives) – vasodilation of capillaries  Flushed skin or pallor – vasodilation  Pruritus (itching)  Conjunctivitis – inflammation of the eye  Rhinitis – mucus gland secretion  Angioedema of lips, eyes, hands, neck, or throat – increased tissue fluid  If larynx – airway obstruction can occur  Classic Signs and Symptoms of Allergy SEVERE Acute reaction affecting respiratory & circulatory systems  Bronchospasm/dyspnea/wheezing – histamine effect of Beta2 receptors in lungs  Hypotension/rapid weak pulse – vasodilation  If severe can lead to cardiovascular collapse (shock)  Tachycardia/arrhythmias  Decreased consciousness and patient responsiveness – oxygen deficiency Progression of Symptoms  Early symptoms self-limiting or resolve after administration of histamine blocker  Patient may deteriorate along continuum of symptoms  Allergic reactions become more severe each time exposed to the allergen  SUDDEN onset with RAPID progression of symptoms over a few minutes is often key to ANAPHYLAXIS  4 Types of Hypersensitivity  Type I – most concerned  Type II  Type III  Type IV  4 Types of Hypersensitivity  Type I – Anaphylactic  Caused by IgE (immunoglobulin E)  Immediate hypersensitivity  May lead to systemic or local Anaphylaxis!  Hives, Asthma, eczema  Bee stings, latex, medications (ie: Penicillin)  4 Types of Hypersensitivity  Type II – Cytotoxic  IgG or IgM  Cell death  Reaction time varies  Blood transfusions 4 Types of Hypersensitivity  Type III – Immune Complex  IgG or IgM  Antigen – antibody Reaction activates inflammatory response Neutrophils attack tissues/body  Rheumatoid arthritis , lupus 4 Types of Hypersensitivity  Type IV – Delayed Hypersensitivity  T-cells  May take more than 12 hours Inflammation develops and can be chronic  Contact dermatitis Metals Treatment  Depends on severity  Attempt to REMOVE causative agent if possible  Emergency Management – MILD Allergic Reaction  Position: supine or comfortable  C-A-B: circulation, airway, breathing  Localized reaction as needed  slight redness or  Definitive Care: itching in area of Administer oral histamine blocker inoculation Chlorpheniramine  Appears self-limiting Diphenhydramine (Benadryl) Observe patient condition  Document  Chlorpheneramine Diphenhydramine HCl *causes less drowsiness Diphenhydramine Emergency Management – SEVERE Allergic Reaction  Symptoms worsening OR  Allergic response begins with severe symptoms  Respiratory (Dyspnea, wheezing)  Cardiovascular (Hypotension, tachycardia, dizziness)  Edema (Facial, laryngeal) Emergency Management – SEVERE Allergic Reaction  Position: supine or comfortable  C-A-B: circulation, airway, breathing, as needed  Definitive Care: Administer IM Epinephrine (0.2mL-0.5mL) Administer O2 4-6 L/minute Monitor vital signs Observe patient Hospital with EMS  Document  Emergency Management – SEVERE Allergic Reaction Epinephrine  Administer epinephrine IM 0.2mL-0.5mL Lateral thigh muscle is best Hold for 10 seconds Massage injection site  Reverses vasodilation, reduces edema, induces bronchodilation, suppresses release of chemical mediators  If no improvement after 5minutes  Repeat dosage  Give up to 3 doses Treatment - SEVERE Allergic Reaction Epinephrine  Most fatalities occur when epi administered too late  Epinephrine  Available in auto-injector  May need to give an additional dose so should have 2 available or vial of epi 1:000 with a syringe  Pediatric Dose Emergency kit should have pre-loaded medium Adult and child EpiPens Prevention of Allergic Reaction  Avoiding allergen  Patients should carry Epipen and be familiar with its use (if they have a known allergy)  Dental healthcare professional can review operation of Epipen with patient – training devices available  Prevention of Allergic Reaction  Allergy testing (MD, allergist)  Skin prick test injects allergen and observes for small, raised, red area within 15 minutes  Skin scratch test place allergen on skin and skin scratched  Radioallergosorbent test (RAST) lab test on blood to test for specific IgE antibodies – most reliable test Reference Malamed, S. F. (2022). Medical emergencies in the dental office. Elsevier. Little, J. W., Miller, C., & Rhodus, N. L. (2017). Little and Falace’s dental management of the medically compromised patient. Mosby. Grimes, E. B. (2014). Medical emergencies: Essentials for the Dental Professional. Prentice Hall