Browse categories and answer follow-up questions to refine your symptom profile.
History
Exposure context
Exposure history
Time since bite or sting
Location of exposure
Geography and setting
Activity at time of exposure
Creature identification
Photo available
Description of markings and size
Number of bites or stings
First aid and prehospital care
Tourniquet use
Incision or suction
Ice or heat application
Pressure immobilization bandage
Alcohol or drug use after exposure
Symptom onset pattern
Immediate onset
Delayed onset
Progressive over hours
OPQRST pain and swelling
OPQRST
Onset
Time pain started relative to exposure
Time swelling started relative to exposure
Provocation/Palliation
Worse with dependent positioning
Worse with movement
Improved with elevation
Response to analgesics
Quality
Burning
Throbbing
Cramping
Paresthesia
Region/Radiation
Bite or sting site
Proximal spread pattern
Severity
Pain score trend
Functional limitation
Timing
Intermittent
Constant
Worsening
Associated symptoms
Associated symptoms
Allergic features
Urticaria
Angioedema
Wheeze
Syncope
Neurotoxic features
Ptosis
Diplopia
Dysarthria
Dysphagia
Weakness
Fasciculations
Hematologic features
Gum bleeding
Epistaxis
Hematuria
Easy bruising
Systemic features
Nausea
Vomiting
Abdominal pain
Diarrhea
Chest pain
Dyspnea
Headache
Fever
Local tissue features
Rapidly progressive swelling
Severe pain out of proportion
Blistering
Necrosis
Baseline and special populations
Baseline and host factors
Pregnancy status
Pediatric age and weight estimate
Immunocompromised state
Asplenia
Liver disease
Kidney disease
Bleeding disorder history
Prior envenomation and antivenom reactions
Alarm Features
Immediate life threats
Immediate life threats
Airway compromise
Stridor
Tongue or laryngeal swelling
Respiratory failure risk
Rapidly progressive bulbar weakness
Hypoventilation
Shock
Hypotension
Altered mental status
Severe anaphylaxis
Hypotension after sting
Bronchospasm
Severe coagulopathy bleeding
Active mucosal bleeding
Intracranial concern symptoms
Vital sign danger thresholds
Vital sign danger thresholds
Systolic blood pressure less than 90 mmHg
Oxygen saturation less than 92 percent on room air
Respiratory rate greater than 30 per minute
Heart rate greater than 130 per minute
Temperature greater than 38.5 C with concerning wound
High risk local findings
High risk local findings
Rapid swelling crossing a joint within hours
Severe pain out of proportion
Bullae or skin discoloration progression
Compartment syndrome concern
Pain with passive stretch
Tense compartments
Time critical escalation triggers
Time critical escalation triggers
If anaphylaxis, IM epinephrine immediately
If progressive neurotoxicity, prepare airway and consult toxicology
If significant coagulopathy or bleeding, antivenom pathway and blood products per protocol
If necrotizing infection concern, surgical consult and broad spectrum antibiotics immediately
Medications
Current and recent agents
Medication exposure
Anticoagulants
Warfarin
Direct oral anticoagulants
Heparins
Antiplatelets
Aspirin
P2Y12 inhibitors
Immunosuppressants
Systemic corticosteroids
Biologics
Beta blockers
Higher risk refractory anaphylaxis
Consider glucagon pathway if shock
ACE inhibitors
Angioedema confounder
Anaphylaxis severity risk
Recent antibiotics
Beta lactam allergy details
MRSA coverage history
ED therapeutics and dosing
ED therapeutics
Anaphylaxis
Epinephrine IM 0.3 mg
Epinephrine IM 0.5 mg
Repeat every 5 to 15 minutes if needed
Nebulized albuterol 2.5 mg
Nebulized albuterol 5 mg
Diphenhydramine IV 25 mg
Diphenhydramine IV 50 mg
Famotidine IV 20 mg
Methylprednisolone IV 125 mg
Crystalloid bolus 20 mL per kg
Analgesia
Acetaminophen PO 1000 mg
Ibuprofen PO 400 mg
Ibuprofen PO 600 mg
Morphine IV 0.05 mg per kg
Morphine IV 0.1 mg per kg
Hydromorphone IV 0.5 mg
Hydromorphone IV 1 mg
Antiemetic
Ondansetron IV 4 mg
Ondansetron IV 8 mg
Tetanus prophylaxis
Td or Tdap per immunization status
Tetanus immune globulin if non immunized and high risk wound
Antivenom safety and premedication
Antivenom safety
Product specific dosing
Local protocol dependent
Early toxicology consultation
Infusion reaction preparedness
Epinephrine at bedside
Large bore IV access
Serum sickness risk counseling
Delayed rash and arthralgia
Occurs days to weeks after antivenom
Diet
Intake and exposures
Intake and exposures
Oral intake tolerance
Hydration status
Alcohol intake after exposure
Energy drinks and caffeine
For marine exposure
Raw seafood ingestion
Recent fish meal
Relevant avoidance considerations
Avoidance considerations
Avoid NSAIDs if active bleeding or severe coagulopathy concern
Avoid alcohol if hypotension or rhabdomyolysis risk
NPO if airway risk or anticipated procedures
Review of Systems
General and infectious
General and infectious
Fever
Chills
Malaise
Rigors
Local warmth and erythema progression
Cardiorespiratory
Cardiorespiratory
Chest tightness
Dyspnea
Wheeze
Palpitations
Syncope
Neurologic and musculoskeletal
Neurologic and musculoskeletal
Headache
Visual changes
Ptosis
Weakness
Paresthesia
Muscle cramps
Dark urine
Gastrointestinal and renal
Gastrointestinal and renal
Nausea
Vomiting
Abdominal pain
Diarrhea
Hematuria
Oliguria
Collateral History and Family History
Collateral and circumstances
Collateral
Witness description of animal
Photo review if available
EMS report
Reliability of timeline
Family history relevant to complications
Family history
Bleeding disorders
Severe allergy and anaphylaxis history
Hereditary angioedema
Household and exposure history
Household and exposure history
Rabies risk animal in home
Sick contacts for cellulitis mimics
Occupational exposure
Animal handling
Marine work
Risk Factors
Exposure and environment risks
Exposure risks
Region with venomous snakes
Region with scorpions
Marine exposure
Jellyfish
Stingray
Sea urchin
Cone snail
Tick exposure
Woods and tall grass
Animal contact
Mammal bite
Dog
Cat
Bat
Wild carnivore
Host and medication risks
Host risks
Anticoagulation
Platelet disorder
Immunocompromised state
Diabetes mellitus (E11.9)
Peripheral arterial disease (I73.9)
Lymphedema
Wound and anatomic risks
Wound risks
Hand bites
Face bites
Deep puncture wounds
Delayed presentation greater than 8 hours
Foreign body risk
Teeth fragments
Spines
Stingers
Differential Diagnosis
Life threatening
Life threatening differential
Anaphylaxis (T78.2)
Rapid onset urticaria and hypotension
Wheeze or airway edema
Neurotoxic envenomation
Progressive cranial nerve dysfunction
Respiratory muscle weakness
Hemotoxic envenomation
Spontaneous bleeding
Rapid coagulopathy
Necrotizing soft tissue infection (M72.6)
Pain out of proportion
Toxic appearance
Compartment syndrome
Pain with passive stretch
Progressive neurologic deficits
Sepsis (A41.9)
Fever with hypotension
Lactate elevation
Common
Common differential
Local allergic reaction
Pruritus predominant
Localized swelling
Cellulitis (L03.90)
Expanding erythema over days
Warmth and tenderness
Abscess (L02.91)
Fluctuance
Purulent drainage
Animal bite wound infection
Early pain and swelling
Lymphangitis
Less common and mimics
Less common and mimics
Brown recluse type necrotic arachnidism
Delayed blister and necrosis
Systemic hemolysis rare
Scorpion envenomation severe syndrome
Autonomic storm
Neuromuscular hyperactivity
Tick paralysis
Ascending weakness
Areflexia
Deep vein thrombosis (I82.409)
Unilateral swelling
Risk factors for thrombosis
Contact dermatitis
Linear vesicles
Pruritus without systemic toxicity
Past Medical History
Relevant conditions
Relevant conditions
Prior severe allergy and anaphylaxis
Asthma (J45.909)
Chronic obstructive pulmonary disease (J44.9)
Chronic kidney disease (N18.9)
Chronic liver disease
Bleeding disorder
Seizure disorder
Prior exposures and procedures
Prior exposures and procedures
Prior antivenom administration
Prior serum sickness
Prior wound infections
Splenectomy history
Baseline function
Baseline function
Baseline mobility
Baseline swallowing function
Baseline respiratory status
Physical Exam
Initial stabilization focused exam
Initial stabilization
Airway patency
Work of breathing
Circulation perfusion
Capillary refill
Skin temperature
Mental status
Full set of vitals with trend
Bite or sting site exam
Local exam
Location and number of punctures
Marking leading edge of erythema and swelling with time
Circumference measurements serial
At bite site level
10 cm proximal
10 cm distal
Compartment syndrome findings
Pain with passive stretch
Paresthesia
Diminished pulses late
Skin findings
Bullae
Ecchymosis
Necrosis
Lymphangitic streaking
Neurovascular status distal
Motor function
Sensation
Capillary refill
System exam for envenomation syndromes
System exam
HEENT
Ptosis
Ophthalmoplegia
Facial swelling
Lungs
Wheeze
Hypoventilation signs
Cardiovascular
Hypotension
Dysrhythmia signs
Neurologic
Bulbar weakness
Generalized weakness
Hyperreflexia or hyporeflexia
Abdomen
Diffuse tenderness
Cramping
Bleeding signs
Gingival bleeding
Petechiae
Oozing at venipuncture sites
Lab Studies
Core labs for moderate to severe presentations
Core labs
CBC
Hemoglobin trend
Platelet count
Electrolytes and renal function
Creatinine
Potassium
Liver enzymes
AST
ALT
Coagulation studies
INR
aPTT
Fibrinogen
Creatine kinase
Rhabdomyolysis screen
Serial if rising
Type and screen
If antivenom planned
If bleeding concern
Bedside and targeted tests
Targeted tests
Glucose
Altered mental status
Pediatric presentations
Venous blood gas
pH
pCO2 mmHg
Lactate mmol/L
Shock concern
Necrotizing infection concern
Urinalysis
Hematuria
Myoglobin concern
Interpretation pearls and pitfalls
Interpretation pearls
Early normal coagulation tests do not exclude evolving hemotoxicity
Rising CK supports systemic myotoxicity
Leukocytosis can be stress response
Creatinine rise can be pigment nephropathy
Hemolysis evaluation if systemic spider bite concern
LDH
Haptoglobin
Imaging
Scoring Systems
Scoring systems
Snakebite severity grading
Local progression rate
Systemic toxicity features
Coagulopathy degree
Hand bite infection risk
Location over tendon sheath
Pain with passive extension
MRI
MRI
Indications
Deep space hand infection
Osteomyelitis concern
Limitations
Not for time critical envenomation decisions
Metal foreign body considerations
CT
CT
Indications
Necrotizing infection evaluation
Deep fascial gas concern
Contrast considerations
Kidney disease risk assessment
Allergy history review
Ultrasound
Ultrasound
Soft tissue POCUS
Abscess versus cellulitis
Foreign body localization
DVT ultrasound
Unilateral swelling mimic
Anticoagulation decision support
Special Tests
Bedside wound and toxin focused tests
Bedside tests
Serial limb exams
Marking swelling borders with time
Serial circumference measurements
Peak flow
Bronchospasm monitoring
Response to therapy
Forced vital capacity
Neurotoxic weakness monitoring
Trend over hours
Rabies and tetanus evaluation
Rabies and tetanus
Rabies risk assessment by animal
Bat exposure
Wild carnivore exposure
Rabies status of animal
Available for observation
Available for testing
Tetanus immunization status
Last dose timing
Primary series completion
ECG
Indications and monitoring
ECG indications
Chest pain
Syncope
Significant hypotension
Autonomic symptoms with scorpion sting concern
High risk patterns
High risk patterns
Ischemic changes
ST elevation
ST depression
Dysrhythmias
Wide complex tachycardia
Bradyarrhythmia with hypotension
QT prolongation
Medication interaction review
Electrolyte correction prompts
Assessment
Working problem list
Working diagnosis
Bite or sting with local reaction
Mild localized swelling
No systemic features
Envenomation suspected
Progressive local effects
Systemic features present
Wound infection suspected
Delayed erythema progression
Purulence
Anaphylaxis (T78.2)
Airway involvement
Hypotension
Severity stratification
Severity stratification
Mild
Local pain and limited swelling
Normal labs
Moderate
Swelling crossing a joint
Early systemic symptoms
Severe
Neurotoxicity
Coagulopathy with bleeding
Hemodynamic instability
Complications to rule out
Complications
Compartment syndrome
Rhabdomyolysis
Acute kidney injury
Secondary bacterial infection
Delayed serum sickness after antivenom
Plan
Approach to the critical patient
First 5 minutes
Cardiac monitoring for systemic toxicity
Two IV lines if moderate to severe presentation
Oxygen if saturation less than 92 percent
IM epinephrine immediately if anaphylaxis
Early toxicology consult for suspected significant envenomation
Local wound care and limb management
Local care
Remove rings and constricting items early
Limb immobilization in functional position
Elevation for comfort after initial assessment
Avoid incision, suction, and cryotherapy
Analgesia titration to effect
Antivenom pathway
Antivenom pathway
Indications
Progressive swelling
Systemic toxicity
Coagulopathy
Dosing
Product specific
Local protocol dependent
Monitoring during infusion
Vitals every 5 to 15 minutes initially
Rash and bronchospasm surveillance
Infection prophylaxis and antibiotics
Antibiotics
Human bite
Amoxicillin clavulanate PO 875 mg every 12 hours
If severe, ampicillin sulbactam IV 3 g every 6 hours
Cat bite
Amoxicillin clavulanate PO 875 mg every 12 hours
Hand bite prophylaxis favored
Dog bite
Amoxicillin clavulanate PO 875 mg every 12 hours
Prophylaxis if hand, deep puncture, or immunocompromised
Penicillin allergy options
Doxycycline PO 100 mg every 12 hours
Metronidazole PO 500 mg every 12 hours
Marine wound risk
Doxycycline PO 100 mg every 12 hours
Third generation cephalosporin per protocol
Rabies and tetanus prophylaxis
Rabies and tetanus
Rabies post exposure prophylaxis
Indicated if high risk exposure and animal not available
Local public health guidance
Rabies immune globulin
Infiltrate into wound when possible
Remainder IM at distant site
Rabies vaccine series
Day 0
Day 3
Day 7
Day 14
Tetanus immunization
Td or Tdap booster per schedule
Tetanus immune globulin if indicated
Reassessment loop
Reassessment loop
Repeat vitals at least every 30 to 60 minutes for evolving envenomation
Repeat focused neuro exam for bulbar progression
Repeat limb measurements every 30 to 60 minutes initially
Repeat coagulation labs every 4 to 6 hours if hemotoxicity concern
Escalate disposition if progression despite therapy
Disposition
ICU and high acuity criteria
ICU criteria
Need for airway support
Progressive neurotoxicity
Refractory hypotension
Active bleeding with coagulopathy
Need for repeated antivenom dosing
Inpatient and observation criteria
Inpatient and observation
Moderate local progression crossing joint
Significant pain requiring parenteral opioids
Abnormal labs
INR elevation
Platelet decrease
Fibrinogen low
High risk wounds
Hand bites
Face bites requiring repair
Discharge criteria
Discharge criteria
No progression after observation period
No systemic symptoms
Stable labs when obtained
Reliable follow up
Clear return precautions understood
Transfer considerations
Transfer considerations
Antivenom unavailable locally
Pediatric critical envenomation
Need for specialty surgery
Hand
Plastics
Discharge Instructions
Copy discharge instructions
Copy discharge instructions
Diagnosis summary
Bite or sting with local reaction
Wound infection treated
Wound care
Keep clean and dry for first 24 hours
Daily gentle wash and new dressing
Swelling care
Elevate when resting
Remove rings and tight items
Medications
Take antibiotics exactly as prescribed if given
Use acetaminophen or ibuprofen for pain if safe for you
Follow up
Primary care within 24 to 72 hours
Earlier reassessment if swelling increases
Return to emergency care now for
Trouble breathing
Fainting
Rapidly spreading swelling
New weakness
Bleeding from gums or urine
Fever or worsening redness
Severe pain not controlled
If antivenom received
Return for rash, fever, or joint pains in the next 1 to 3 weeks
Inform clinicians you received antivenom
References
Guidelines and key sources
References
World Health Organization snakebite envenoming guideline 2016
Wilderness Medical Society clinical practice guideline for pit viper envenomation 2015
Centers for Disease Control and Prevention rabies postexposure prophylaxis guidance 2024
Infectious Diseases Society of America skin and soft tissue infections guideline 2014
American Heart Association anaphylaxis emergency management updates 2020
Project instructions source
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.