VACCINE-RELATED ALLERGIC REACTIONS Management of Anaphylaxis IERHA Immunization Program September 2016
VACCINE-RELATED ADVERSE EVENTS Local reactions pain, edema, erythema Systemic reactions fever, lymphadenopathy Allergic reactions IgE Mediated Long term complications
ALLERGENS & ANTIBODIES A QUICK REVIEW Allergen - specific type of antigen which can trigger an abnormal immune response in certain individuals Antibodies - proteins manufactured by the immune system to fight off antigens; produced during the immune response (IgE, IgA, etc)
ALLERGIC REACTION = Exposure to allergen Large quantities of IgE bind to basophiles and mast cells (specialized cells of immune system that contain chemicals that assist in the immune response) Antigen-antibody complex is formed
Allergic Reaction cont d IgE/mast cell/basophile cells release histamine, heparin, other substances Histamine - principal chemical involved in allergic reaction potent substance which causes bronchospasm, increased vascular permeability (causes leakage of fluid from circulatory system into surrounding tissues)
Vaccine-related IgE-Mediated Allergic Reactions are RARE IgE may be made to: Gelatin MMR, rabies, varicella, yellow fever, influenza, Japanese encephalitis vaccines Egg influenza, MMR, yellow fever Latex Specific immunizing agent diphtheria, tetanus, pertussis Antibiotics, preservatives, etc.
IS IT ANAPHYLAXIS??? Fainting - characterized by pallor, slow pulse, salivation, nausea, vomiting, and sweating Anaphylactic reactions - often occur within minutes; initially characterized by apprehension (sense of impending doom), flushing, generalized itching, hives, increased heart rate, and loss of consciousness
DISTINGUISHING FEATURES BETWEEN FAINTING AND ANAPHYLAXIS Rapidity of onset is key differentiator With fainting, subject changes from normal to unconscious state within seconds With anaphylaxis, changes develop over several minutes; may involve multiple body systems - usually evident within 15 minutes after injection
DISTINGUISHING FEATURES BETWEEN FAINTING AND ANAPHYLAXIS Fainting - more common, benign, managed by placing the patient in recumbent position Fainting - sometimes accompanied by brief clonic seizure activity; generally requires no specific treatment or investigation Rarely is unconsciousness the sole manifestation of anaphylaxis; it may progress to unconsciousness only as a late event in severe cases
Anaphylaxis = Multi-system disorder Anaphylaxis is set apart from simple allergic reactions (eg hives, allergic rhinitis, asthma) by simultaneous involvement of several organ systems Presence of skin symptoms is key to differentiating anaphylaxis from similar clinical syndromes of different cause (syncope, septic shock, mycocardial infarction, etc)
SIGNS & SYMPTOMS OF ANAPHYLAXIS INTEGUMENTARY SYSTEM Occur in 90% of anaphylactic reactions! Generalized hives (hallmark sign) Flushed or red skin Swelling Generalized itching with or without skin rash Prickle sensation Localized injection site hives Red and itchy eyes
RESPIRATORY SYSTEM o Bilateral wheeze (bronchospasm) o High pitched wheeze or cough o Upper airway swelling (lip, tongue, throat, larynx) o Respiratory distress rapid breathing, cyanosis, grunting o Persistent dry cough o Hoarse voice o Difficulty breathing without wheeze or stridor o Sensation of lump in throat o Sneezing, runny nose
CARDIOVASCULAR SYSTEM Hypotension Clinical diagnosis of shock tachycardia and decreased LOC or loss of consciousness and reduced pulse volume (weak, thready)
Other symptoms may include: GASTROINTESTINAL SYSTEM Nausea & vomiting, abdominal pain, diarrhea GI symptoms are more common with ingested allergens. NERVOUS SYSTEM Increased anxiety, headache, dizziness, disorientation, seizures, unresponsiveness GENERAL SYMPTOMS Pins and needles sensation, complaint of general malaise
WHAT CAUSES DEATH FROM ANAPHYLAXIS? Shock hypotension and cardiac arrest Upper airway compromise Lower airway compromise (bronchospasm) WHO IS AT RISK FOR FATAL ANAPHYLAXIS? Asthmatics, especially if poorly controlled Persons taking beta-blockers Persons with cardiac compromise
ANAPHYLAXIS MANAGEMENT Initial assessment rapid history and physical exam observing for signs & symptoms of anaphylaxis CALL 911 ABCD S of resuscitation: Airway Breathing Circulation Drug treatment
ANAPHYLAXIS MANAGEMENT Monitor vital signs pulse, blood pressure, respiratory rate Rule of thumb skin symptoms plus any other symptoms treat as anaphylaxis However, hemodynamic collapse might occur rapidly with little or no cutaneous or respiratory manifestations
TREATMENT OF ANAPHYLAXIS EPINEPHRINE!!! Epinephrine (1:1000) - life-saving - first and most important drug to give! There is no absolute contraindication to epinephrine administration 0.01 ml/kg (maximum 0.5 ml per injection) should be given IM into the vastus lateralis (thigh muscle) not at site of immunization Same dose can be repeated every 10 minutes to a maximum of 3 doses
Epinephrine Class: Sympathomimetic Action: Bronchodilator Indications: Anaphylaxis, Cardiac Arrest Precautions: Underlying CV disease Side effects: Palpitations, anxiousness, N/V Dosage: 0.01 ml/kg IM Counteracts histamine-induced vasodilation Increases heart rate, cardiac contractility Acts on smooth muscles of bronchial tree ( bronchospasm) Suppresses body s immune response (slows down histamine cascade)
MB HEALTH DOSING PROTOCOL for EPINEPHRINE 2 6 months 0.07 ml 6 12 months 0.07ml 0.1 ml 12 18 months 0.1 ml 0.15 ml 18 months 4 years 0.15 ml 5 years 0.2 ml 6 9 years 0.3 ml 10 13 years 0.4 ml >14 years 0.5 ml
WHAT IS THE ROLE OF ANTIHISTAMINES? NOT life-saving! Will not prevent fatal anaphylaxis Used primarily to treat skin symptoms (relief of itchiness and hives) Intermediate interval before drug takes effect Diphenhydramine 50mg/ml 2.5 mg/kg to a maximum of 50 mg should be given IM DO NOT REPEAT!
Diphenhydramine Class: Antihistamine Actions: Blocks histamine receptors Indications: Anaphylaxis Precautions: Asthma, Hypotension Side Effects: Sedation, dries bronchial secretions Dosage: 50 mg/ml IM
MB HEALTH DOSING PROTOCOL for DIPHENHYDRAMINE Under 2 years Age 2 to 4 years Age 5 to 11 years > 12 years 0.25 ml 0.50 ml 0.50-1.00 ml 1.00 ml
IMPORTANT POINTS Never give diphenhydramine before epinephrine Muscle of choice for epi is the thigh because of better absorption If there are skin symptoms plus any one other symptom give EPI! Other important treatment measures include oxygen, IV fluids, corticosteroids it is therefore vital that the person be transported to hospital asap
WHEN IN DOUBT GIVE EPINEPHRINE!!!
References Manitoba Health Protocol for Management of Suspected Anaphylactic Shock (2007) Dr. Jan Roberts Anaphylaxis presentation (2005) British Columbia Communicable Disease Control - Immunization Manual - Management of Anaphylaxis in a Non-Hospital Setting (2013) National Advisory Committee on Immunization Canadian Immunization Guide. (on-line edition 2013) - Public Health Agency of Canada
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