AnaphylaxisMANAGEMENT

SYSTEMIC AND MISCELLANEOUS PRESENTATIONS · 12 SECTIONS

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480 items

☷ Legend

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Cardiovascular Presentations66▾

Respiratory Presentations47▾

Neurological Presentations77▾

Gastrointestinal Presentations63▾

Genitourinary and Reproductive Presentations44▾

Infectious Disease Presentations146▾

Trauma Presentations88▾

Toxicologic Presentations67▾

Psychiatric Presentations25▾

Musculoskeletal and Rheumatologic Presentations89▾

Dermatology Presentations21▾

Environmental and Exposure Presentations26▾

Hematologic and Oncologic Presentations30▾

Pediatric-Specific Presentations13▾

Endocrine and Metabolic Presentations42▾

ENT and Maxillofacial Presentations21▾

Ophthalmologic Presentations15▾

Obstetric Presentations17▾

Systemic and Miscellaneous Presentations15▾

Allergic Transfusion Reaction Anaphylaxis Angioedema Benedikt's Syndrome Cannabis-induced hyperemesis Eczema (acute flare)Gradenigo's Syndrome Horner's Syndrome (Acute)Huntington's Disease (Acute Presentation)Kanavel's Signs Lemierre's Syndrome Radiation exposure Retained products of conception Sever's Disease Urticaria

01Approach to the Critical Patient/attcp64

Recognition and immediate priorities

›Time-critical framework

›Suspected anaphylaxis

›Acute illness with airway compromise

›Acute illness with breathing compromise

›Acute illness with circulation compromise

›Acute illness with skin mucosal involvement plus respiratory compromise

›Acute illness with skin mucosal involvement plus hypotension or end-organ hypoperfusion

›After likely allergen exposure with two or more systems involved

›Skin mucosal

›Respiratory

›Cardiovascular

›Gastrointestinal

›If any airway or hemodynamic compromise then treat as anaphylaxis

›Early epinephrine

›Do not delay for tests

›Remove trigger if possible

›Stop infusion or medication

›Remove stinger

›Discontinue latex exposure

Resuscitation and monitoring

›Initial stabilization bundle

›Escalate to resuscitation bay for any hypotension or airway symptoms

›Team activation

›Respiratory therapy and airway support

›Pharmacy for epinephrine infusion setup

›Monitoring

›Continuous cardiac monitoring

›Dysrhythmia detection during epinephrine therapy

›Continuous pulse oximetry

›Trending response to therapy

›Noninvasive blood pressure cycling every 1-2 minutes

›If shock then arterial line when feasible

›Access

›Two large-bore IV lines

›If difficult then IO access

Airway and breathing escalation triggers

›Airway risk stratification

›High-risk airway features

›Voice change or hoarseness

›Laryngeal edema concern

›Stridor

›Upper airway narrowing

›Tongue or floor-of-mouth swelling

›Rapid progression risk

›Drooling or inability to handle secretions

›Impending obstruction

›Severe agitation or fatigue

›Ventilatory failure risk

›If progressive airway symptoms then early definitive airway

›Most experienced laryngoscopist

›Video laryngoscopy preferred when feasible

›Prepare for front-of-neck access

›Cricothyrotomy kit at bedside

Hemodynamic targets and shock approach

›Perfusion goals

›Mean arterial pressure at least 65 mmHg in adults

›Adjust for baseline chronic hypertension

›Normal mental status or improving

›Surrogate of cerebral perfusion

›Urine output at least 0.5 ml/kg/hour

›For prolonged resuscitation

›Shock pattern recognition

›Distributive shock physiology

›Warm extremities possible early

›Wide pulse pressure possible

›If hypotension then immediate IM epinephrine and fluid bolus

›Epinephrine first-line vasopressor in anaphylaxis

02History/hx60

Presentation pattern and triggers

›Core history elements

›Symptom onset time

›Minutes to 2 hours after exposure typical

›Suspected trigger category

›Foods

›Medications

›Hymenoptera venom

›Latex

›Exercise or cofactor-associated

›Idiopathic

›Exposure route

›Ingested

›Injected

›Inhaled

›Contact

›Prior reactions

›Prior anaphylaxis episodes

›Known allergens

›Prior epinephrine use and response

Symptom clusters by system

›Symptom domains

›Skin and mucosal

›Urticaria

›Pruritus

›Flushing

›Angioedema

›Respiratory

›Dyspnea

›Wheeze

›Stridor

›Chest tightness

›Cardiovascular

›Lightheadedness

›Syncope

›Hypotension symptoms

›Gastrointestinal

›Abdominal pain

›Vomiting

›Diarrhea

Risk modifiers and cofactors

›Severity risk modifiers

›Asthma history

›Poor control

›Cardiovascular disease

›Coronary artery disease

›Heart failure

›Mast cell disorder history

›Prior elevated tryptase

›Systemic mastocytosis

›Beta-blocker use

›Reduced response to epinephrine

›ACE inhibitor use

›Angioedema overlap

›Cofactors

›Exercise

›Food-dependent exercise-induced

›Alcohol

›Increased susceptibility

›NSAID use

›Increased susceptibility

›Intercurrent infection

›Increased susceptibility

03Physical Exam/exam38

Primary survey findings

›System-based findings

›Airway

›Lip or tongue swelling

›Uvular edema

›Voice changes

›Stridor

›Breathing

›Work of breathing

›Wheeze

›Hypoxia

›Circulation

›Capillary refill time

›Skin temperature and perfusion

›Tachycardia or bradycardia

›Hypotension

Skin mucosal and GI exam

›Cutaneous and mucosal assessment

›Urticaria distribution

›Generalized vs localized

›Angioedema sites

›Periorbital

›Lip

›Tongue

›Conjunctival injection

›Allergic involvement

›Gastrointestinal assessment

›Abdominal tenderness

›Severe pain concern for alternative diagnosis

›Ongoing emesis

›Aspiration risk

Pitfalls and alternate patterns

›Diagnostic pitfalls

›Absent skin findings

›Possible in severe or rapid shock

›Isolated hypotension after allergen exposure

›Consider anaphylaxis despite minimal rash

›Isolated bronchospasm

›Consider anaphylaxis trigger and treat accordingly

›Refractory hypotension

›Consider inadequate epinephrine dosing or ongoing exposure

04Differential Diagnosis/ddx36

Life-threatening mimics

›Immediate threat differentials

›Asthma exacerbation

›No hypotension and no multi-system involvement more likely

›Upper airway obstruction non-allergic

›Foreign body

›Epiglottitis

›Angioedema bradykinin-mediated

›ACE inhibitor associated

›Hereditary angioedema

›Septic shock

›Fever and infectious source clues

›Pulmonary embolism

›Pleuritic pain and risk factors

›Myocardial infarction

›Chest pain with ischemic pattern

›Dysrhythmia

›Primary arrhythmia causing syncope

Related allergic syndromes

›Allergic spectrum differentials

›Isolated urticaria

›No respiratory or hemodynamic involvement

›Anaphylactoid non-IgE mediated reactions

›Clinically treated the same as anaphylaxis

›Red man syndrome and infusion reactions

›Typically slower infusion-associated flushing

›Scombroid poisoning

›Flushing and GI symptoms after fish ingestion

Coding considerations

›Medical coding

›ICD-10 codes

›T78.2XXA anaphylactic shock unspecified initial encounter

›T78.0XXA anaphylactic reaction due to food initial encounter

›T80.5XXA anaphylactic reaction due to serum initial encounter

›T63.44XA toxic effect of bee venom initial encounter

›T88.6XXA anaphylactic reaction due to adverse effect of correct drug initial encounter

›SNOMED CT concepts

›39579001 anaphylaxis

›62315008 anaphylactic shock

05Laboratory Tests/lt20

Core labs in moderate to severe presentations

›Baseline and severity assessment

›Point-of-care glucose for altered mental status

›Hypoglycemia alternative cause of symptoms

›Venous blood gas for severe respiratory distress

›pH and pCO2 in mmHg

›Lactate for shock or persistent hypotension

›Trend with resuscitation

›Electrolytes and renal function

›Fluid resuscitation and vasopressor planning

Allergy mediator testing

›Tryptase and related testing

›Serum tryptase for suspected anaphylaxis with unclear trigger

›Peak typically 1-2 hours after symptom onset

›Declines toward baseline by about 6 hours

›If available then baseline tryptase after recovery

›Mast cell disorder screening

Pitfalls and limitations

›Test interpretation cautions

›Normal tryptase does not exclude anaphylaxis

›More likely to rise in hypotension and venom reactions

›Leukocytosis and stress hyperglycemia nonspecific

›Do not anchor on infection without evidence

06Diagnostic Tests/dt46

Scoring Systems

›Diagnostic criteria and grading

›NIAID FAAN clinical criteria framework

›Acute skin mucosal involvement plus respiratory compromise

›Acute skin mucosal involvement plus reduced blood pressure or end-organ dysfunction

›After likely allergen exposure with two or more systems involved

›Skin mucosal

›Respiratory

›Reduced blood pressure or end-organ dysfunction

›Persistent gastrointestinal symptoms

›After known allergen exposure with reduced blood pressure

›Adults systolic blood pressure less than 90 mmHg or greater than 30 percent decrease from baseline

›Children age-specific low systolic blood pressure or greater than 30 percent decrease

›WAO anaphylaxis severity grading concepts

›Mild

›Skin mucosal symptoms only

›Moderate

›Respiratory symptoms without hypoxia

›GI symptoms with significant distress

›Severe

›Hypoxia

›Hypotension or collapse

›Neurologic compromise

MRI

›Limited role imaging considerations

›MRI indications for alternative diagnosis

›Neurologic deficits not explained by hypoperfusion

›Suspected spinal pathology unrelated to allergic reaction

›MRI contraindications and constraints

›Unstable airway or hemodynamics

›Delayed access and monitoring challenges

›Alternative diagnosis evaluation

›CT indications when symptoms atypical

›Severe abdominal pain with peritoneal signs

›Suspected pulmonary embolism features

›Suspected aortic pathology features

›CT risks

›Iodinated contrast reactions

›Treat reactions as anaphylaxis if occur

Ultrasound

›Point-of-care ultrasound adjuncts

›Shock differentiation support

›Cardiac function

›Hyperdynamic ventricle in distributive physiology

›IVC assessment

›Collapsibility suggesting hypovolemia component

›Lung ultrasound

›B-lines for cardiogenic pulmonary edema alternative

›Pleural effusion alternative

07Disposition/dispo28

Observation and admission criteria

›Post-treatment risk stratification

›Observation candidates

›Complete symptom resolution after treatment

›No hypotension episode

›No airway edema progression

›Admission indications

›Recurrent symptoms requiring repeat epinephrine

›Hypotension or shock

›Persistent bronchospasm or hypoxia

›Airway involvement

›Tongue or laryngeal edema concern

›Epinephrine infusion required

Observation duration and biphasic reaction risk

›Monitoring time concepts

›Minimum observation interval

›At least 4-6 hours for resolved mild to moderate reactions

›Extended observation or admission interval

›At least 12-24 hours for severe reactions

›Prior biphasic reaction history

›Delayed epinephrine administration

›Unknown trigger with ongoing risk

Transfer and consultation triggers

›Escalation needs

›ICU level care triggers

›Epinephrine infusion

›Persistent hypotension

›Mechanical ventilation

›Specialist follow-up needs

›Allergy immunology referral

›Mast cell disorder evaluation for recurrent idiopathic episodes

08Treatment/t89

First-line epinephrine and immediate therapies

›Epinephrine first-line

›Intramuscular dosing

›Adults 0.3-0.5 mg IM of 1 mg/ml in anterolateral thigh

›Repeat every 5-15 minutes if persistent symptoms

›Pediatrics 0.01 mg/kg IM of 1 mg/ml in anterolateral thigh

›Maximum single dose 0.5 mg

›Repeat every 5-15 minutes if persistent symptoms

›Auto-injector dosing

›0.15 mg for smaller children per device labeling

›Use when available and appropriate size

›0.3 mg for older children and adults per device labeling

›Use when available and appropriate size

›Intravenous infusion for refractory symptoms

›Indication

›Persistent hypotension after IM epinephrine and fluids

›Ongoing severe bronchospasm after IM epinephrine

›Preparation safety

›Dedicated infusion pump

›Continuous cardiac monitoring

›Starting dose range

›0.05-0.1 microg/kg/min

›Titrate every 2-5 minutes to perfusion targets

›Alternative adult starting dose

›1-4 microg/min

›Titrate upward as needed

›Airway and oxygenation support

›Oxygen therapy

›Nonrebreather for hypoxia

›Escalate based on work of breathing

›Nebulized bronchodilator

›Salbutamol 2.5-5 mg nebulized

›Repeat as needed for wheeze

›Ipratropium 0.5 mg nebulized

›Add for severe bronchospasm

›Nebulized epinephrine for upper airway symptoms

›Racemic epinephrine 2.25 percent 0.5 ml nebulized

›Repeat as needed while preparing definitive airway

Fluids and vasopressors

›Volume resuscitation

›Isotonic crystalloid bolus

›Adults 1-2 litres rapid infusion

›Repeat based on blood pressure and perfusion

›Pediatrics 20 ml/kg bolus

›Repeat up to 60 ml/kg for shock with reassessment

›Additional vasopressors when needed

›If refractory to epinephrine infusion then adjunct vasopressor

›Norepinephrine infusion per shock protocol

›Titrate to mean arterial pressure target

›Vasopressin adjunct

›Consider in catecholamine-refractory shock

Adjunct medications

›H1 antihistamine for cutaneous symptoms

›Diphenhydramine 25-50 mg IV or IM

›Sedation risk and delirium risk

›Cetirizine 10 mg PO when able

›Less sedation than first-generation agents

›H2 blocker adjunct

›Famotidine 20 mg IV or PO

›Adjunct only

›Corticosteroid adjunct

›Methylprednisolone 125 mg IV

›Consider for asthma comorbidity and prolonged symptoms

›Prednisone 40-60 mg PO when able

›Discharge taper individualized

›Antiemetic adjunct

›Ondansetron 4-8 mg IV or ODT

›Supportive symptom control

Refractory anaphylaxis special situations

›Beta-blocker associated refractory symptoms

›Glucagon therapy

›Adults 1-5 mg IV over 5 minutes

›Follow with infusion 5-15 microg/min

›Titrate to hemodynamic response

›Pediatrics 20-30 microg/kg IV over 5 minutes

›Maximum 1 mg

›Follow with infusion 5-10 microg/min

›Adverse effects

›Vomiting risk

›Aspiration precautions

›Bradykinin-mediated angioedema overlap

›If isolated angioedema without urticaria then consider bradykinin mechanism

›Epinephrine still appropriate if airway compromise

›Targeted therapies per angioedema protocol if confirmed

Evidence levels and guideline statements

›Guideline aligned care concepts

›Epinephrine as first-line therapy

›Class I recommendation in major allergy society guidance

›Antihistamines not effective for airway or shock

›Adjunct only

›Corticosteroids not reliable for biphasic prevention

›Use as adjunct for comorbid asthma or prolonged symptoms

›ACEP Level B or C alignment

›Early epinephrine prioritized over adjunctive therapies

09Special Populations/sp28

Pregnancy

›Pregnancy considerations

›Maternal stabilization priority

›Maternal oxygenation and perfusion as fetal protection

›Epinephrine use

›Not contraindicated in anaphylaxis

›Same IM dosing as nonpregnant adults

›Positioning

›Left uterine displacement in late pregnancy

›Improve venous return

›Obstetric consultation triggers

›Persistent maternal hypotension

›Uterine contractions or vaginal bleeding

Geriatric

›Older adult considerations

›Higher baseline cardiovascular risk

›Monitor for ischemia during catecholamine therapy

›Medication interactions

›Beta-blocker and alpha-blocker use more common

›Lower physiologic reserve

›Lower threshold for admission after severe episode

Pediatrics

›Pediatric considerations

›Weight-based dosing emphasis

›Epinephrine 0.01 mg/kg IM of 1 mg/ml

›Fluid bolus 20 ml/kg isotonic crystalloid

›Age-specific hypotension thresholds

›Use pediatric shock references for low systolic blood pressure

›Common triggers by age

›Foods in younger children

›Venom and medications in older children

10Background/b39

Epidemiology

›Frequency and outcomes

›Common triggers

›Foods

›Medications

›Venom

›Biphasic reaction concept

›Recurrence after initial resolution

›Higher risk with severe initial presentation

›Fatality risk factors

›Delayed epinephrine

›Severe asthma

›Cardiovascular disease

Pathophysiology

›Mechanisms

›Mast cell and basophil mediator release

›Histamine

›Leukotrienes

›Prostaglandins

›Resulting physiologic effects

›Vasodilation and capillary leak

›Bronchospasm

›Mucosal edema

›Phenotypes

›IgE-mediated

›Non-IgE mediated

›Idiopathic

Therapeutic Considerations

›Rationale for epinephrine

›Alpha-1 effects

›Vasoconstriction and reduced mucosal edema

›Beta-1 effects

›Increased cardiac output

›Beta-2 effects

›Bronchodilation

›Reduced mediator release

›Adjunct limitations

›Antihistamines

›Symptom relief for hives only

›Corticosteroids

›Delayed onset

›Uncertain impact on biphasic reactions

11Patient Discharge Instructions/pdi23

copy discharge instructions

›Discharge packet

›Diagnosis

›Anaphylaxis

›Medications and devices

›Epinephrine auto-injector prescribed

›Carry at all times

›Demonstration of correct use

›Practice trainer when available

›Second auto-injector recommended

›Some reactions require repeat dosing

›Avoidance plan

›Identified trigger avoidance

›Label reading and cross-contamination precautions for food allergy

›Follow-up

›Allergy immunology appointment

›Primary care follow-up within 1 week

›Return to emergency department immediately for

›Any breathing difficulty

›Throat tightness or voice change

›Fainting or severe dizziness

›Worsening swelling of lips or tongue

›Recurrent hives with vomiting or abdominal pain

›Need for epinephrine use

12References/r9

Clinical guidelines and evidence sources

›Key sources

›World Allergy Organization anaphylaxis guidance

›Diagnostic criteria and management recommendations

›AAAAI ACAAI practice parameters for anaphylaxis

›Epinephrine as first-line therapy

›NIAID FAAN anaphylaxis criteria publication

›Clinical diagnostic framework

›ACEP emergency care guidance concepts

›Early epinephrine emphasis in ED pathways

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Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

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