Presentation on theme: "Urticaria, Angioedema and Anaphylaxis in the Emergency Department"— Presentation transcript:
1Urticaria, Angioedema and Anaphylaxis in the Emergency Department Back to Basics 2011Jennifer Clow MD, CCFP (EM)With slides by: Anita Pozgay, MD, FRCPC EM
2Case OneA 7 year old comes in to the ED after an possible exposure to peanut butterHe has a severe nut allergy for which he was prescribed an EpiPenHe was recently admitted to PICU for a severe asthma attack but was not intubatedMom gave him some oral Benadryl and he is no longer itchy but still has lip swelling
4Case One continuedHe is sent for a CXR due to decreased air entry in the lower lobesWhile in radiology, he becomes acutely SOB and his lip becomes more swollenWhat do you do now?
5Case TwoA 45 y o woman involved in a MVC needs a CT abdo after she is stabilized in the EDShe received 2 L NS for a hypotensive episode and her BP is now 120/70She has a positive FAST U/SAlthough her CXR is normal she has palpable lower rib fractures & a distended abdomen
6Case Two continued She is given both oral and IV contrast for her CT She becomes hypotensive again!What do you do now?There is no rash
7Case Three A 67 y o man is stung by an insect while gardening He developed pruritus, dizziness, and SOB 20 min later so he called 911He self-treated with Benadryl po and was given another 50 mg IV by EMS due to persistent sx and rashHe is now asymptomatic and refusing transport to hospital
8Case Three: Do you transport? EMS convinced him to get “checked out” in the hospitalOn arrival, he becomes hypotensive, and his hives reappeared, along with facial edemaAn ECG shows T wave inversion in his lateral leadsPHx: MI, HTN, IV contrast allergyMeds: ASA, metoprolol, lisinopril
11DefinitionsAnaphylaxis: a severe systemic allergic reaction involving 2 or more systems* hives/angioedema NOT universally present!Anaphylactic Shock: above, plus hypotension and other signs of shockAllergic reactions: localized reaction, involving a single system; e.g. urticaria, angioedema, contact dermatitis, rhinoconjunctivitis
12Urticaria versus Angioedema Both characterized by transient, pruritic, red wheals on raised serpiginous bordersurticaria due to edema of dermisangioedema due to edema of subcutaneous tissues
14AKA HivesRaised, well-circumscribed areas of edema and erythema involving the dermis and epidermisIntensely pruriticMay be acute or chronic (>6 weeks)Multiple types: IgE-mediated, chemical-induced, cholinergic, cold-induced, autoimmune, etc.
20PathophysiologyMast cells and basophils release histamine, bradykinin, leukotrienes, prostaglandins into the dermisCauses fluid extravasation… leads to lesionPruritis is due to histamine release into the dermisMultiple triggers: IgE mediated, others
21CausesCauses: found in 40-60% of acute urticaria, and 10-20% chronic urticariaInclude:Infections, pregnancy, other medical conditionsFoods, drugs, latexEnvironmental factorsStressCold/heat, exercise
22History Previous episodes/causative factors Medical history, medications, allergiesPossible precipitants:Recent illness or travelNew medications or IV contrastFoods, pets, exposuresChanges in perfumes, lotions, clothesExercise, temperature extremes, stress
23Physical Exam Identify and confirm urticarial diagnosis Dermographism? Look for precipitants/other illnesses:Signs of infections: e.g. URTI, fungal infectionSigns of liver/thyroid diseaseAngioedema, respiratory changes (edema, wheezes)Joint examinationEnsure no signs of anaphylaxis are present
24Treatment H1-blockers i.e. diphenhydramine, hydroxyzine H2-blockers i.e. ranitidineAct synergistically with H1 blockersDoxepin 10-25mg tid-qidGlucocorticoids e.g. prednisoneStabilize mast cells, stopping histamine releaseAnti-inflammatory effect
26Deep, subcutaneous, submucosal edema due to increased vascular permeability May be episodic and self-limited, or recurrentMay involve skin, buccal mucosa/tongue, larynx or GI mucosaUsually presents with urticaria: mast-cell mediated in these cases
30Types Hereditary C1-esterase inhibitor deficiency Acquired: autoimmune/lymphoprolif. disordersDrug-induced (e.g. ACEI)Urticaria-associatedIdiopathic (most cases)Urticaria-associated is mast-cell mediated, all others are kinin-mediated
31History Hereditary/idiopathic/drug-induced: Urticaria-associated: Episodic, self-limiting episodes of edemaSkin swelling, tongue swelling, abdominal painLook for triggersUrticaria-associated:Look for potential triggers: drugs, allergens, food allergies, hymenopteraHistory of atopy
32Physical ExamAcute onset of well-demarcated cutaneous edema of distensible tissuesUsually face, limbs, genitalsAssess airwayAbdominal examination
33Treatment AIRWAY management Mild Angioedema Severe Angioedema Intubate early if any questionMild AngioedemaRemove offending agent; self-limitedSevere AngioedemaH1, H2 blockers, corticosteroidsEpinephrine
35Definition Severe allergic reaction (IgE-mediated) Requires prior-sensitization and re-exposureRapid in onset, may cause deathUsually includes prominent dermal and systemic manifestationsFull syndrome involves urticaria/angioedema, respiratory manifestations +/- GI upsetAnaphylactic shock: above + hypotension
36Anaphylactic vs. Anaphylactoid Anaphylactoid has the same clinical features as anaphylaxis but is not IgE mediatedInstead it is due to direct mast cell degranulation and thus, does not require prior sensitization
37PathophysiologySensitization occurs when IgE adheres to the mast cell Ag (allergen)IgE specificDegranulation of mast cellmediators
38PathophysiologyRe-exposure leads to antigen binding, and rapid release of mediators:Histamines, leukotrienes, prostaglandins, tryptaseLeads to rapid onset of:Increased secretion from mucus membranesIncreased bronchial smooth muscle toneDecreased vascular smooth muscle toneIncreased capillary permeability
39EpidemiologyLikely under reported due to lack of recognition or self treatment in the fieldin Ontario: 4 cases/ 1 millionin Germany: 10 cases/in Minnesota, U.S.A.: 17/19,122 visitsin Brisbane, Australia: 1/440 visits
44Physical Examination Vitals, ABC’s General appearance Skin Respiratory Cardiovascular
45Grading of Anaphylaxis GradeSkinGI tractRespCVNeuro1Local pruritus, hives, mild lip swellingOral “tingling”, pruritus2Generalized pruritus, hives, flushing, angioedemaAbove plus nausea +/- emesisNasal congestion/sneezingActivity change3Any of aboveAny of above + repetitive vomitingRhinorrhea, sensation of throat tightnessTachy( > 15 bpm)Above plus anxiety4Any of above + diarrheaHoarsenessdysphagia, SOB, cyanosisAbove + arrhythmia +/- dec BPdizzinessFeeling of impending doom5Any above + stool incont.Any above + resp arrestBrady +/- card arrestLOC
46Management Questions? What is the first line of therapy? When do you give IV vs IM epi?Do all patients need Epinephrine; corticosteroids?What is the role of combined H1 & H2 blockers?Who needs to be monitored? Referred?Who needs an EpiPen?
47Key Management of Anaphylaxis 1st line of therapy:AWARENESSRECOGNITIONTREAT QUICKLYCALL FOR BACK-UP!
49Management: Adult Epi dosing Epinephrine:0.3 mg (0.3 ml) 1:1000 solution IM(NOT SC or IV)may repeat in 5 min X 1(empirical only but safe)
50Epi: Pediatric Dosing (0.01 ml/kg) Age (yrs) Volume of Dose (mg)1:1000(1mg/ml)ml 0.1ml 0.2> ml 0.3
51EPI cautions: Co-morbidities Thyroid diseaseCocaine addictsCAD on BBlockers, ACEiDepression using MAOIs or TCAsBblockers blunt the response to epi and this is both B1 and B2. ACEi blunt the catecholamine response ( ACE/Nor-Epi/Epi rise) with shock.
52Mechanisms of Epinephrine Alpha agonist effects increase peripheral resistance, raise BP, reduce vascular leakageBeta agonist effects cause bronchodilation, positive cardiac inotropy/chronotropy (caution in CAD pts!)
53Dangers of Epinephrine IV Only use IV Epi if patient has refractory shock not responding to fluid bolus firstdose 0.1 mg (10 ml) 1:100,000 dilution over 10 minutesmust be on cardiac monitorcaution in elderly or those with CADmay cause supraventricular/ventricular dysrhythmias!
54Management Do all patients need Epi? Epinephrine reverses mediator release while antihistamines (H1) do notEpinephrine should be used for all systemic signs of allergy: airway edema (includes tongue/lips), SOB, cyanosis, hypotension
55Management: Do all patients need Corticosteroids? Corticosteroids take 4-6 hours to worktheoretically blunt the multi-phasic reaction of anaphylaxisthe quicker the onset of anaphylaxis the worse the reaction/quicker resolution less likely to relapseCaution in IV steroids esp if given in bolus doses; case reports of anaphylaxis!Oral form preferred if possible
57Management: What is the role of combined H1 & H2 Antagonists? RCT, N=91 w/ allergic syndromes50 mg Benadryl (H1) & saline vs. 50 mg Benadryl & 50 mg Ranitidine (H2) IVEndpoints of resolution of urticaria, angioedema, or erythemaalso measured subjective improvement & vitalsLin et al., Improved outcomes in patients with acute allergic syndromes who are treated with combined H1 & H2 antagonists, Annals of Emergency Medicine 36(5) 2000.
58Histamines: ResultsStatistically significant diminution of angioedema and/or urticaria with addition of H2 blockerstudy too small to determine if H2 blockers helpful in anaphylaxis (those with respiratory compromise &/or hypotension)also significant decrease in HR in Rx group
60Case One: Peanut allergy in asthmatic A 7 year old comes in to the ED after an possible exposure to peanut butterHe has a severe nut allergy for which he was prescribed an EpiPenHe was recently admitted to PICU for a severe asthma attack but was not intubatedMom gave him some oral Benadryl and he is no longer itchy but still has lip swelling
61Case One continuedHe is sent for a CXR due to decreased air entry in the lower lobesWhile in radiology, he becomes acutely SOB and his lip becomes more swollenWhat do you do now?
62Case 1 Conclusion He needs IM Epi! (He weighs 30 kg and thus 0.3 mg IM is fine.)O2, IV fluids, cardiac monitoringConsider Ventolin neb (esp if concurrent asthma)
63Case Two : MVC Management A 45 y o woman involved in a MVC needs a CT abdo after she is stabilized in the EDShe received 2 L NS for a hypotensive episode and her BP is now 120/70, HR 100She has a positive FAST U/SAlthough her CXR is normal she has palpable lower rib fractures & a distended abdomen
64Case Two continued She is given both oral and IV contrast for her CT She becomes hypotensive again!What do you do now?There is no rash
65Case 2: ConclusionIs she in hypovolemic shock or anaphylactic? doesn’t matter b/c both require IV crystalloids!There may be no rash initiallyLook for airway compromise/swelling: intubate?IV contrast reactions are anaphylactoid and so prior sensitization not necessary (thus may be no prior hx of anaphylaxis)If no response to fluids give IV epi 1st via slow infusion, except if pulseless then may give IV bolus
68Case Three A 67 y o man is stung by an insect while gardening He developed pruritus, dizziness, and SOB 20 min later so he called 911He self-treated with Benadryl po and was given another 50 mg IV by EMS due to persistent sx and rashHe is now asymptomatic and refusing transport to hospital
69Case Three: Do you transport? EMS convinced him to get “checked out” in the hospitalOn arrival, he becomes hypotensive, and his hives reappeared, along with facial edemaAn ECG shows T wave inversion in his lateral leadsPHx: MI, HTN, IV contrast allergyMeds: ASA, metoprolol, lisinopril
70Case 3 Management: Refractory Anaphylaxis Biphasic (multi?) reactions can occur typically after 3-4 hours but as late as 72 hours later!Beware of the patient with increased age and co-morbidities (eg. CAD) b/c anaphylaxis can cause cardiac ischemiaB-Blockers & ACEi blunt the catecholamine response
71Management Refractory Anaphylaxis: Glucagon Glucagon: increases inotropy/chronotropy & causes smooth muscle relaxation independent of B receptorsDose: 1-5 mg in adults ( mg in kids) IV/IM
72Management: Disposition & Follow-up Inquire about possible antigen exposureThose with systemic reactions require a prescription for and instruction on how to use a EpiPenA Medic Alert Bracelet is usefulFollow-up with an allergist for skin testing should be arranged particularly if the allergen is unknown
74SummaryAcute anaphylaxis is often poorly recognized & treated due to the protean clinical features and variation in the speed of onseta trigger is often not foundPruritis is a universal feature and should differentiate anaphylaxis from asthmaExpedious treatment w/ epi is necessary & thus patient education on its use is essential
76Case of EIA28 year old male, after eating spaghetti and then playing soccer 1 hr later, developed urticaria & dizzinessattempted to drive to hospital but pulled over because worseEMS vitals: BP 80/42, HR 90, RR 24Rx: w/ epi and 1 litre NSIn ED: BP 130/85, chest was clear and “hives” gone but skin still edematous
77Exercise Induced Anaphylaxis Clinical features indistinguishable from allergen induced anaphylaxisfood dependent & food independent forms (also cholinergic urticaria)mechanism not fully known, but thought exercise lowers threshold for mast cell degranulation esp after a food allergen triggers an IgE response
79Natural History of EIAN= 365 respondents with 10 yr hx of EIA to 75 item questionaireEIA if anaphylactic Sx with exercise but not with passive warmingShadick, Nancy A., et al. The Natural History of Exercise-Induced Anaphylaxis: Survey results from a 10-year follow-up study, J Allergy Clin Immunol 1999; 104:
80Results of Survey frequency of attacks lesson over time a wide range of activities associated but more CV demand more likely70% had atopy or family hx of itsubjects avoided attacks by not exercising in humid weather or high allergy seasonsno single trigger identified; most common foodH1 blockers/ epi were used by 30% emergently; Role of prophylaxis?