Hypersensitivity Diagnosis in the ER

Hypersensitivity : 

Hypersensitivity Josyann Abisaab, MD Department of Emergency Medicine New York Presbyterian Hospital- Weill Cornell Medical Center

Outline : 

Outline Types of Hypersensitivity Anaphylaxis Disposition Prevention

Definition of Hypersensitivity : 

Definition of Hypersensitivity Undesirable reactions produced by the normal immune system.

Classification of Hypersensitivity : 

Classification of Hypersensitivity Type I: Immediate/Anaphylactic Type II: Cytotoxic Antibody Reaction Type III: Immune Complex Reaction Type IV: Delayed-Type Hypersensitivity Type V: Stimulatory Hypersensitivity

Type I- Immediate hypersensitivity : 

Type I- Immediate hypersensitivity Provoked by reexposure to a specific antigen. IgE mediated Mast cells and Basophils stimulation Release of Histamine and other chemicals Vasodilation, mucous secretion, bronchospasm

Type I- Immediate : 

Type I- Immediate Acute response within 1 hour Late-phase response 4-6 hours after original reaction, can last 1-2 days Local vs. systemic

Type I- Immediate : 

Type I- Immediate Urticaria (hives) Angioedema Allergic conjunctivitis Allergic Rhinitis Allergic Asthma Anaphylaxis

Type II- Cytotoxic Antibody Reaction : 

Type II- Cytotoxic Antibody Reaction Antigen is on the patient’s own cell surfaces Mediated by IgG and IgM Complement activation Cell lysis and death Reaction takes hours to a day

Type II- Cytotoxic : 

Type II- Cytotoxic Transfusion reactions Rh incompatibility Autoimmune hemolytic anemia Goodpasture’s syndrome Pemphigus ITP Rx: anti-inflammatory + immunosuppressive agents

Type III- Immune Complex Hypersensitivity : 

Type III- Immune Complex Hypersensitivity Antigen-antibody complexes deposit in tissue Antigen is soluble- not attached to organ involved Classical pathway of complement activation Takes hours to days to develop

Type III- Immune Complex : 

Type III- Immune Complex Serum sickness SLE Rheumatoid arthritis Erythema nodosum Arthus reaction (Farmer’s Lung) Immune complex glomerulonephritis Rx: anti-inflammatory agents

Type IV- Delayed-Type Hypersensitivity : 

Type IV- Delayed-Type Hypersensitivity Mediated by T-Lymphocytes Takes 2-3 days Contact dermatitis (poison ivy, nickel) PPD Transplant rejection (GVHD) Rx: corticosteroids + other immunosuppressive agents

Contact Dermatitis : 

Contact Dermatitis

Delayed Hypersensitivity Reactions : 

Delayed Hypersensitivity Reactions

Type V- Stimulatory Hypersensitivity : 

Type V- Stimulatory Hypersensitivity IgG stimulate their target Graves Disease Myasthenia Gravis Ligand induced apoptosis Stevens Johnson Syndrome/Toxic Epidermal Necrolysis (TENS)

Type V- Stimulatory : 

Type V- Stimulatory Stevens Johnson Syndrome TENS

Anaphylaxis : 

Anaphylaxis Case Presentation: 39 y.o male BIBA in respiratory distress with agonal pulse. Paramedics report patient was helping a friend paint when he was stung by a bee. He walked into the house, saying:”I don’t feel good” and collapsed. Intubated at scene, en route given endotracheal and IV Epi, IV Benadryl

Anaphylaxis : 

Anaphylaxis Case Presentation: On arrival in ED, patient intubated, cyanotic from neck up, CPR in progress 2nd Large bore IV, wide open fluids Dopamine drip Epnephrine drip Central line Isuprel drip, Levophed drip Monitor: agonal wide-complex

Anaphylaxis : 

Anaphylaxis Case presentation: TVP failed to capture After 20 min prehospital and 30 min hospital resuscitation, no response. Patient died. Cause: “Fatal Anaphylactic Reaction”

What is Anaphylaxis? : 

What is Anaphylaxis? “A systemic reaction of multiple organ systems to an antigen-induced IgE-mediated immunologic mediator release in a previously sensitized individual”

What does the word mean? : 

What does the word mean? “ana” means against or backwards “phylaxis” means guard or protect Anaphylaxis= “without protection” Prophylaxis= “for protection”

What is Anaphylactoid? : 

What is Anaphylactoid? A nonimmunologic reaction Not mediated by IgE Direct histamine release Same manifestations & treatment as anaphylaxis Causes: RCM, opiates, ACEI, exercise, blood products, gammaglobulin, NSAIDs, ASA

Anaphylaxis: How does it manifest? : 

Anaphylaxis: How does it manifest? Clinical severity varies from mild to fatal Majority of reactions are respiratory and dermatologic Innocent early findings may progress to lethal over a short time

What causes the deaths? : 

What causes the deaths? Laryngeal edema and acute bronchospasm >70% Circulatory collapse >25% other <5% - ?brain ?MI

In USA : 

In USA 30,000 emergency room visits each year 400 to 800 deaths/year IV penicillin accounts for 100 to 500 deaths per year Hymenoptera stings account for 40 to 100 deaths per year Risk factors: protracted course, betablockers, adrenal insufficiency

Histamine : 

Histamine Prime mediator of both local and systemic effects H1: smooth muscle contraction,  vascular permeablility H2: gastric acid secretion, release of more histamine,  vascular permeability H3: inhibition of central and peripheral neurotransmitter release, inhibition of further histamine

Clinical expression depends on: : 

Clinical expression depends on: Degree of hypersensitivity Quantity, route, rate of antigen exposure Pattern of mediator release Target organ sensitivity and responsiveness

Timing : 

Timing Uniphasic Biphasic Protracted Laryngeal edema more common in biphasic (40%) or protracted (57%) cases

Usual culprits : 

Usual culprits

Clinical manifestations : 

Clinical manifestations Skin: urticaria and angioedema Respiratory: cough, dyspnea, wheezing, hoarseness

Clinical manifestations : 

Clinical manifestations Lightheadedness or syncope Nasal congestion and sneezing Ocular itching and tearing Cramping abdominal pain with N/V/D Headache Sense of impending doom ↓ level of consciousness

Examination : 

Examination Urticaria

Examination : 

Examination Angioedema

Examination : 

Examination Angioedema of oropharynx

Examination : 

Examination Conjunctivitis, rhinitis Tachypnea, tachycardia, hypotension Laryngeal stridor, hoarseness Wheezing, ronchi, diminished air flow

Optimal Management : 

Optimal Management High index of suspicion Early diagnosis Pharmaceutical intervention Observation Disposition

Index of suspicion : 

Index of suspicion The motto of Emergency Medicine: TREAT FIRST ASK QUESTIONS LATER

Treating mild anaphylaxis : 

Treating mild anaphylaxis Urticaria, rhinitis, conjunctivitis, mild bronchospasm Epinephrine 1:1000 0.3cc IM may repeat every 5-20min prn 0.01mg per kg in children Benadryl 50 mg po or IM Consider: H2-blocker, prednisone, inhaled beta-agonists

Steroids : 

Steroids Benefit 6-12 hrs after administration May prevent biphasic or protracted reaction

Myth: Epi is dangerous : 

Myth: Epi is dangerous Reality: Risks of anaphylaxis far outweigh risks of Epi administration Minimal cardiovascular effects in children (Simons et al, 1998) Caution in: elderly, known cardiac disease and tachyarrythmias

Treating moderate anaphylaxis : 

Treating moderate anaphylaxis Angioedema or hypotension with BP>80mmHg Epinephrine 1:1000- 0.3 cc IM Benadryl 50mg IM or IV Pepcid IV Solumedrol 40-125mg IV Oxygen, IVF, cardiac monitor

Treating severe anaphylaxis : 

Treating severe anaphylaxis Laryngeal edema, respiratory failure, shock Epinephrine 1:10,000- 1cc IV over 5 min, repeat every 3-5 min prn Benadryl 50-100mg IV over 3 min H2 blockers Solumedrol Nebulizers: racemic epi, albuterol

Laryngeal edema : 

Laryngeal edema Chin lift, jaw thrust Naso-or oropharyngeal airway Racemic epi 0.5 cc neb Heliox (Boorstein et al, AEM, 1989) Tracheal intubation prn Surgical airway prn

Persistent bronchospasm : 

Persistent bronchospasm Albuterol by continuous nebulization Aminophylline 5.6 mg/kg IV over 20-30 min Atrovent by nebulization Heliox Steroids Intubation

Persistent hypotension : 

Persistent hypotension Trendelenberg 2 largebore IV’s infusing crystalloid Monitor urine output and CVP PASG Consider: Naloxone 0.4-0.8mg IV Vasopressors: dopamine, isoproterenol, levophed

What about Glucagon? : 

What about Glucagon? When epi contraindicated, may be an option Positive inotropic and chronotropic cardiac effects Consider in patients: On beta blockers With known CAD Pregnant women No response to other drugs

Disposition : 

Disposition Systemic features: observe for 6-8 hours Cannot predict biphasic reaction Admission mandatory for: Moderate to severe reaction, even if they respond rapidly to Rx Consider admission for: Elderly CAD Asthma On beta blocker

May be discharged home if : 

May be discharged home if Mild anaphylaxis No hypotension No signs of airway obstruction Rapid response to ED therapy Observed for 6 hours without recurrence Safe discharge to care of responsible adult

Outpatient management : 

Outpatient management 4 day course of Benadryl Q6h 4 day course of Pepcid BID 4 day course of Prednisone 50mg/day (Ellis et al, CMAJ, 2003) Referral to an Allergist

Prevention : 

Prevention Avoid the food Aerosol spray containing Epi-Primatene or Medihaler-Epi Epi-Pen Medic Alert bracelet

Board Type Questions : 

Board Type Questions A 27 year old man presents after a syncopal event following a long run. He c/o lightheadedness and itching, along with swelling of his hands and feet. His BP is 68/36 mmHg and pulse is 160. Lung examination shows he has diffuse wheezing. His blood glucose is 95 mg/dl. The most important initial IV therapy would be: Epinephrine Diphenhydramine Methylprednisolone Normal Saline Pepcid

Board Type Questions : 

Board Type Questions Type I Hypersensitivity: occurs 24 hours after the initial stimulus is produced by IgE antibodies is cell mediated is best treated with steroids is diagnosed by measuring serum histamine levels

Board Type Questions : 

Board Type Questions A 45 year old man with no PMH was playing golf when he complained of a sting on his hand, followed by shortness of breath and loss of consciousness. EMS at scene report a BP 70/40, HR 140 and bilateral wheezing. The most likely diagnosis is: Vasovagal syncope Asthma Psychogenic syncope related to bad golfing day Anaphylactic shock Myocardial Infarction

Board Type Questions : 

Board Type Questions A 19-year-old woman with a past history of seasonal allergic rhinitis is referred to the ED from her family doctor’s office. She had received her routine injection of allergen immunotherapy (ragweed). Twenty minutes later, she began to notice itching in the palms of her hands, followed by shortness of breath and a sensation of throat swelling. In the ED, patient is noted to be flushed, sweating and in moderate distress. Her BP is 110/60 and her HR is 120. She is speaking in full sentences. The most appropriate initial emergency treatment would be: Epinephrine 1:10,000- 1cc IV Racemic Epi 0.5 cc neb Epinephrine 1:1000- 0.3 cc IM Albuterol neb Benadryl 50mg po

Board Type Questions : 

Board Type Questions A 40 year old woman presents to the ED 30 minutes after eating chicken with cashews at a chinese restaurant. Patient complains of hives, itchy eyes, throat tightness as well as mild shortness of breath. The astute ED intern makes the diagnosis of urticaria and mild anaphylaxis. She administers IM Epi and Benadryl with immediate resolution of symptoms. Patient now feels well and wants to go home. You agree with patient and write discharge order You give her steroids first then discharge her You recommend observation in the ED for at least 6 hours You recommend discharge home under the care of an adult after 2 hours You recommend admission to the hospital

Any questions? : 

Any questions?