Envenomation (snake, spider, insect)MANAGEMENT

ENVIRONMENTAL AND EXPOSURE PRESENTATIONS · 12 SECTIONS

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637 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▾

Acute Mountain Sickness Arterial Gas Embolism Bee-Wasp Sting (Anaphylaxis)Chilblains Ciguatera Fish Poisoning Coral Cut Decompression Sickness Electrical Burn Injury Envenomation (snake, spider, insect)High Altitude Cerebral Edema (HACE)High Altitude Pulmonary Edema (HAPE)High-altitude illness Hypothermia Hypothermia (Mild)Hypothermia (Severe)Immersion Foot Lightning Strike Injury Scombroid Fish Poisoning Scorpion Envenomation Sea Urchin Injury Shark Bite Snake Envenomation Spider Bite (Black Widow)Spider Bite (Brown Recluse)Stingray Spine Injury White Phosphorus Burn

Hematologic and Oncologic Presentations30▾

Pediatric-Specific Presentations13▾

Endocrine and Metabolic Presentations42▾

ENT and Maxillofacial Presentations21▾

Ophthalmologic Presentations15▾

Obstetric Presentations17▾

Systemic and Miscellaneous Presentations15▾

01Approach to the Critical Patient/attcp63

Immediate threats

›Time critical stabilization

›Airway compromise

›Stridor

›Oropharyngeal edema

›Respiratory failure

›Hypoventilation

›Progressive bulbar weakness

›Shock

›Anaphylaxis physiology

›Hemorrhagic physiology from venom induced coagulopathy

›Rapid neurologic decline

›Cranial nerve dysfunction

›Ascending paralysis

›Limb threat

›Rapidly progressive swelling crossing a joint

›Compartment syndrome concern

Early high yield actions

›First minutes bundle

›Resuscitation bay triggers

›Hypotension

›Hypoxia

›Rapidly progressive facial or neck swelling

›Venom exposure control

›Remove rings and constrictive clothing

›Limb at heart level

›Analgesia and anxiolysis

›Opioid analgesia for severe pain

›Benzodiazepine for severe muscle spasm

›Antivenom readiness

›Immediate poison center consultation

›Species specific antivenom availability check

Monitoring and targets

›Physiologic monitoring

›Continuous pulse oximetry

›Oxygen saturation trend

›Early desaturation trigger for airway planning

›Cardiac monitoring

›Dysrhythmia surveillance

›QT prolongation risk with some antiemetics and analgesics

›Serial extremity checks

›Mark leading edge of swelling with time noted in chart

›Circumference measurements proximal and distal

›Hemodynamic targets

›Systolic blood pressure appropriate for age and baseline

›Urine output trend when critically ill

Antivenom reaction preparedness

›Infusion safety

›Anaphylaxis kit at bedside

›Epinephrine IM dosing ready

›Airway equipment ready

›Immediate hypersensitivity signs

›Urticaria

›Bronchospasm

›Delayed serum sickness risk

›Fever

›Arthralgias

Consultation triggers

›Team activation

›Toxicology or poison center

›Any systemic toxicity

›Any coagulopathy concern

›Surgery

›Necrotizing soft tissue infection concern

›Compartment syndrome concern

›ICU

›Need for airway support

›Need for antivenom with systemic instability

02History/hx73

Exposure characterization

›Exposure details

›Time of bite or sting

›Symptom onset time

›Time to progression

›Species identification

›Photo of animal or insect if safe

›Geographic region and habitat

›Number of bites or stings

›Multiple sting risk for venom load

›Swarm exposure risk

›Anatomic location

›Face and neck higher airway risk

›Distal extremity common snakebite site

Prehospital interventions and pitfalls

›Field actions

›Tourniquet use

›Duration

›Neurovascular symptoms after release

›Incision suction cryotherapy

›Skin injury risk

›No proven venom removal benefit

›Pressure immobilization

›Relevant for some neurotoxic elapid bites

›Not for cytotoxic pit viper bites with swelling

›Medications taken

›NSAIDs and bleeding risk

›Sedatives and hypoventilation risk

Symptom inventory by toxidrome

›Local toxidrome

›Pain severity

›Rapid severe pain

›Delayed pain after brown recluse pattern

›Swelling progression

›Proximal spread

›Crossing joints

›Bleeding and bruising

›Oozing at puncture site

›Ecchymosis

›Neurotoxic toxidrome

›Diplopia ptosis dysarthria

›Bulbar symptoms

›Dysphagia

›Paresthesias and fasciculations

›Perioral tingling

›Muscle twitching

›Respiratory symptoms

›Dyspnea

›Weak cough

›Systemic inflammatory toxidrome

›Nausea vomiting abdominal pain

›Autonomic features

›Diaphoresis

›Chest pain and palpitations

›Catecholamine surge pattern in latrodectism

›Hypertension

›Anaphylaxis toxidrome

›Urticaria angioedema wheeze

›Prior sting reactions

›Epinephrine autoinjector use

Risk factors and modifiers

›Patient factors

›Age and weight

›Pediatric venom dose relative burden

›Frailty and reserve

›Comorbidities

›Asthma and severe bronchospasm risk

›Cardiovascular disease and shock vulnerability

›Medications

›Anticoagulants and bleeding risk

›Beta blockers and refractory anaphylaxis risk

›Allergy history

›Prior antivenom exposure

›Equine ovine antiserum reactions

›Pregnancy status

›Fetal monitoring needs

›Maternal hypoxia risk

03Physical Exam/exam66

General and vital signs pattern recognition

›Global assessment

›Toxic appearance

›Diaphoresis

›Agitation

›Vital sign trends

›Hypotension

›Hypertension and tachycardia

›Airway and breathing

›Voice change

›Increased work of breathing

Local wound and limb exam

›Bite or sting site

›Puncture marks

›Single puncture possible

›Multiple punctures possible

›Erythema edema ecchymosis

›Rate of spread

›Lymphangitic streaking

›Bullae and necrosis

›Hemorrhagic bullae concern

›Necrotic center concern

›Retained stinger or foreign body

›Visible stinger

›Palpable foreign body

›Neurovascular status

›Capillary refill and pulses

›Pulse deficit

›Coolness

›Motor and sensory function

›Paresthesia distribution

›Weakness progression

›Compartment syndrome indicators

›Pain out of proportion

›Pain with passive stretch

Neurologic exam

›Neurotoxicity screen

›Cranial nerves

›Ptosis

›Ophthalmoplegia

›Bulbar function

›Dysarthria

›Drooling

›Respiratory muscle function

›Single breath count trend

›Neck flexor weakness

›Autonomic findings

›Mydriasis

›Diaphoresis

Anaphylaxis and systemic findings

›Hypersensitivity findings

›Urticaria and flushing

›Generalized distribution

›Rapid onset

›Angioedema

›Lips tongue

›Periorbital swelling

›Wheeze and bronchospasm

›Prolonged expiration

›Silent chest risk

›GI involvement

›Repetitive vomiting

›Abdominal cramping

PITFALLS

›Common diagnostic traps

›Overcalling compartment syndrome early in snakebite

›Swelling related pain without true compartment pressure elevation

›Fasciotomy worsened outcomes risk

›Mislabeling skin necrosis as infection early

›Venom induced tissue injury without bacterial infection

›Antibiotics not routinely indicated

04Differential Diagnosis/ddx49

Limb swelling and pain

›Limb swelling differential

›Venomous snake envenomation

›Pit viper pattern

›Elapid neurotoxic pattern

›Cellulitis

›ICD-10 L03

›Fever and progressive erythema over days

›Necrotizing soft tissue infection

›ICD-10 M72.6

›Pain out of proportion systemic toxicity

›Deep vein thrombosis

›ICD-10 I82

›Unilateral swelling without puncture site findings

›Compartment syndrome

›ICD-10 T79.A

›Passive stretch pain neuro deficits

Coagulopathy and bleeding

›Bleeding differential

›Venom induced consumption coagulopathy

›Defibrination

›Thrombocytopenia

›Anticoagulant related bleeding

›Warfarin DOAC exposure

›Elevated INR pattern

›Liver failure coagulopathy

›Chronic stigmata

›Mixed factor deficiency

Neurotoxicity and paralysis

›Neuro weakness differential

›Neurotoxic snake envenomation

›Cranial nerve involvement

›Descending paralysis

›Tick paralysis

›Ascending weakness

›Rapid improvement after tick removal

›Guillain Barre syndrome

›Albuminocytologic dissociation

›Areflexia

›Botulism

›Pupil involvement

›Constipation prodrome

Systemic pain spasm syndromes

›Pain spasm differential

›Latrodectism black widow

›Diffuse muscle cramping

›Autonomic storm

›Acute abdomen

›Peritonitis signs

›Localized tenderness pattern

›Acute coronary syndrome

›Ischemic symptoms

›ECG changes

05Laboratory Tests/lt49

Initial baseline studies

›Baseline labs

›Complete blood count

›Platelets for thrombocytopenia

›Leukocytosis nonspecific stress marker

›Electrolytes renal function

›Creatinine for rhabdomyolysis and dehydration risk

›Potassium for hemolysis and renal dysfunction

›Creatine kinase

›Myonecrosis screening

›Rhabdomyolysis trend

›Liver enzymes

›Baseline for systemic illness

›Hemolysis indirect marker when paired with bilirubin

›Glucose

›Stress hyperglycemia

›Hypoglycemia confounder for altered mental status

Hemostasis assessment for snake envenomation

›Coagulation profile

›INR and PT

›Venom induced factor consumption

›Baseline anticoagulant confounder

›aPTT

›Mixed pathway involvement

›Heparin confounder

›Fibrinogen

›Defibrination marker

›Antivenom response trend

›D dimer

›Consumption and fibrinolysis marker

›Limited specificity

›Type and screen

›Transfusion readiness

›Massive bleeding contingency

Infection and inflammation adjuncts

›Infection adjuncts

›Lactate

›Shock marker

›Necrotizing infection risk marker

›Blood cultures

›Systemic infection concern

›Immunocompromised host

›C reactive protein

›Limited specificity

›Trend support for infection when combined with exam

Point of care testing

›Point of care tools

›Venous blood gas

›Hypercapnia in respiratory weakness

›pH trend in shock

›Pregnancy test

›Medication risk assessment

›Imaging decision context

06Diagnostic Tests/dt60

Scoring Systems

›Decision tools and criteria

›Snakebite Severity Score

›Local effects domain

›Swelling and ecchymosis extent

›Bullae and necrosis presence

›Systemic effects domain

›Hypotension vomiting altered mental status

›Neurotoxicity signs

›Hematologic domain

›Platelets low

›Fibrinogen low or INR elevated

›Clinical use

›Antivenom consideration support

›Serial reassessment framework

›Anaphylaxis clinical criteria

›Acute onset with skin mucosal involvement plus respiratory compromise

›Wheeze stridor hypoxemia

›Persistent hypotension

›Two system involvement after likely allergen

›Skin mucosal

›Respiratory GI cardiovascular

›Hypotension after known allergen exposure

›Systolic blood pressure low for age

›Syncope or collapse

MRI

›MRI considerations

›Deep soft tissue evaluation

›Myositis

›Osteomyelitis late presentation

›Neuro symptoms alternative diagnosis

›Brainstem stroke concern

›Spinal cord pathology concern

›Limitations

›Delays definitive therapy

›Motion artifact in painful patients

›CT applications

›Necrotizing soft tissue infection evaluation

›Gas in soft tissues

›Deep fascial edema

›Facial or neck swelling

›Airway threat anatomy

›Abscess alternative diagnosis when delayed presentation

›Neuro symptoms alternative diagnosis

›Intracranial hemorrhage concern

›Stroke pathway activation if focal deficits

›Limitations

›Early necrotizing infection may have normal CT

›Contrast considerations in kidney injury

Ultrasound

›Ultrasound and POCUS

›Retained foreign body or stinger

›Hyperechoic linear structure

›Local fluid collection

›Soft tissue evaluation

›Cellulitis cobblestoning

›Abscess fluid collection

›Vascular evaluation

›DVT assessment for unilateral swelling

›Arterial flow when pulse concern

›Shock evaluation

›Cardiac function and tamponade screen

›IVC size trend in volume assessment

07Disposition/dispo33

Observation and admission criteria

›Level of care decisions

›ICU indications

›Airway edema

›Progressive neurotoxicity

›Step down or monitored bed

›Systemic symptoms without instability

›Antivenom infusion with reaction risk

›ED observation

›Mild local effects with stable labs

›Need for serial limb and coag reassessment

›Transfer criteria

›Antivenom not available locally

›Pediatric severe envenomation without ICU support

Suggested monitoring windows

›Time based reassessment

›Anaphylaxis after sting

›Observation for biphasic reaction risk

›Longer observation for severe reactions or multiple epinephrine doses

›Suspected pit viper bite without initial progression

›Serial exams and coagulation reassessment

›Delayed coagulopathy counseling when discharged

›Black widow syndrome

›Discharge after pain control and stable vitals

›Admission for refractory pain or hypertension

Discharge readiness

›Discharge criteria

›No progression of swelling on serial exams

›Stable circumference and markings

›No new bullae

›Stable hemostasis labs when relevant

›Platelets stable

›Fibrinogen stable and INR stable

›Reliable follow up plan

›Return precautions understood

›Access to recheck labs if needed

08Treatment/t147

General measures for all bites and stings

›Supportive care bundle

›Wound care

›Clean with soap and water

›Avoid incision suction

›Tetanus prophylaxis

›Vaccination status review

›Tdap update per routine schedule

›Limb management

›Heart level positioning

›Splinting for comfort and decreased venom spread by movement

›Pain control

›Opioid analgesia titrated to effect

›Avoid NSAIDs when coagulopathy concern

›Antibiotics strategy

›No routine prophylaxis for uncomplicated bites

›Targeted therapy for clear infection or high risk wounds

›Rabies prophylaxis

›Not indicated for snakes spiders insects

›Consider only if mammal bite co exposure

Anaphylaxis from insect stings

›Anaphylaxis protocol

›Epinephrine IM

›Adult epinephrine 1 mg/ml 0.3 mg to 0.5 mg IM lateral thigh

›Repeat every 5 minutes to 15 minutes as needed

›Early repeat if persistent hypotension or bronchospasm

›Pediatric epinephrine 1 mg/ml 0.01 mg/kg IM lateral thigh

›Maximum single dose 0.3 mg in many protocols

›Repeat every 5 minutes to 15 minutes as needed

›Airway and oxygen

›High flow oxygen for hypoxemia

›Goal oxygen saturation above baseline and clinical improvement

›Early airway planning for progressive edema

›Nebulized bronchodilator for wheeze

›Albuterol dosing per age and weight

›Add ipratropium for severe bronchospasm

›Fluids

›Crystalloid bolus for hypotension

›Adult 10 ml/kg to 20 ml/kg as clinically indicated

›Pediatric 20 ml/kg isotonic crystalloid

›Adjuncts

›H1 antihistamine for cutaneous symptoms

›Diphenhydramine adult 25 mg to 50 mg IV or PO

›Diphenhydramine pediatric 1 mg/kg IV or PO maximum 50 mg

›H2 blocker option

›Famotidine adult 20 mg IV or PO

›Famotidine pediatric 0.5 mg/kg IV or PO maximum 20 mg

›Corticosteroid option

›Methylprednisolone adult 125 mg IV

›Methylprednisolone pediatric 1 mg/kg to 2 mg/kg IV

›Refractory shock

›Epinephrine infusion initiation for persistent hypotension after IM dosing and fluids

›Start low dose and titrate to perfusion targets

›Continuous cardiac monitoring

Snake envenomation

›Suspected venomous snakebite management

›Antivenom indications

›Progressive swelling crossing a joint

›Rapid progression on serial marking

›Severe pain out of proportion

›Systemic toxicity

›Hypotension

›Recurrent vomiting or altered mental status

›Hematologic toxicity

›Platelets low

›Fibrinogen low or INR elevated

›Neurotoxicity

›Ptosis ophthalmoplegia

›Bulbar weakness

›Pit viper antivenom pathway

›Regional first line antivenom per poison center

›Initial control dosing per product protocol

›Repeat dosing for failure of initial control

›Coagulation reassessment schedule

›Repeat INR platelets fibrinogen after antivenom

›Serial reassessment for delayed coagulopathy

›Blood products approach

›Avoid routine FFP cryoprecipitate platelets before adequate antivenom control

›Use blood products for life threatening bleeding after antivenom initiation

›Neurotoxic elapid pathway

›Early airway planning

›Declining single breath count

›Bulbar dysfunction with aspiration risk

›Species specific antivenom coordination

›Poison center and regional antivenom bank

›Transport planning if not available locally

Spider envenomation

›Latrodectism black widow syndrome

›Symptom control

›Opioid analgesia

›Titrate to pain control

›Monitor for hypoventilation

›Benzodiazepine for muscle spasm

›Diazepam or lorazepam per institutional dosing

›Avoid oversedation in older adults

›Antivenin considerations

›Severe refractory pain or hypertension

›Toxicology consultation

›Hypersensitivity risk assessment

›Observation for symptom recurrence

›Pain rebound after initial control

›Delayed allergic reaction counseling

›Loxoscelism brown recluse syndrome

›Local care

›Cold packs early for pain and inflammation

›Elevation for swelling

›Necrosis management

›Early surgical debridement avoidance

›Demarcation delay days to weeks

›Worsening tissue loss risk with early surgery

›Infection management only if clinical infection

›Purulence and fever

›Progressive cellulitis pattern

›Systemic hemolysis monitoring

›Hemoglobin trend

›Indirect bilirubin and LDH if hemolysis concern

Scorpion and other arthropod envenomation

›Scorpion sting neurotoxicity

›Supportive care

›Benzodiazepine for severe agitation or muscle jerking

›Airway support for excessive secretions or respiratory compromise

›Antivenom considerations

›Severe cranial nerve dysfunction

›Drooling

›Abnormal eye movements

›Pediatric severe symptoms

›Toxicology consultation

›Regional antivenom availability

›Fire ant stings

›Cutaneous care

›Topical corticosteroid for pruritus

›Oral antihistamine for itching

›Anaphylaxis pathway when systemic symptoms

›Epinephrine IM as above

›Observation for recurrence

Complications and escalation

›Compartment syndrome pathway

›High suspicion features

›Progressive neurovascular compromise

›Pain with passive stretch plus tense compartments

›Compartment pressure measurement consideration

›Objective confirmation when diagnosis unclear

›Surgery consultation early

›Fasciotomy caution in snakebite

›Prefer antivenom and elevation first when consistent with venom edema

›Fasciotomy reserved for confirmed compartment syndrome with objective data

›Secondary infection pathway

›Infection indicators

›Fever after initial stabilization period

›Purulent drainage

›Antibiotic selection

›Coverage based on local patterns and wound type

›Tetanus update completed

09Special Populations/sp30

Pregnancy

›Pregnancy considerations

›Maternal stabilization priority

›Epinephrine for anaphylaxis when indicated

›Antivenom when maternal indications met

›Fetal considerations

›Viability dependent fetal monitoring when systemic toxicity

›Obstetrics consultation for moderate to severe envenomation

›Medication considerations

›Avoid teratogenic agents without clear benefit

›Prefer established anaphylaxis medications when indicated

Geriatric

›Older adult considerations

›Higher adverse effect risk

›Sedation and falls with benzodiazepines

›Respiratory depression with opioids

›Comorbidity interactions

›Anticoagulants and bleeding risk

›Cardiovascular disease and hypertension complications

›Disposition bias toward observation

›Limited reserve

›Higher complication risk

Pediatrics

›Pediatric considerations

›Weight based dosing

›Epinephrine 0.01 mg/kg IM

›Fluid bolus 20 ml/kg for shock

›Venom burden

›Higher severity with same venom amount

›Lower threshold for antivenom when progression

›Monitoring needs

›Early airway planning with neurotoxicity

›Longer observation for evolving swelling

10Background/b36

Epidemiology

›Frequency patterns

›Snakebites

›Outdoor exposure and warm season clustering

›Most bites on distal extremities

›Spider bites

›True medically significant bites uncommon

›Misdiagnosis common in skin infections

›Hymenoptera stings

›Very common exposures

›Anaphylaxis uncommon but high consequence

Pathophysiology

›Venom mechanisms

›Hemotoxic venoms

›Consumption coagulopathy via procoagulant toxins

›Endothelial injury with local hemorrhage

›Cytotoxic venoms

›Local tissue necrosis

›Secondary inflammation and edema

›Neurotoxic venoms

›Presynaptic or postsynaptic neuromuscular blockade

›Bulbar and respiratory muscle weakness

›Allergic mechanisms

›IgE mediated mast cell degranulation in stings

›Biphasic reaction possibility

Therapeutic Considerations

›Treatment principles

›Antivenom

›Neutralization of circulating venom

›Best effect before severe tissue injury established

›Supportive care

›Airway protection in neurotoxicity

›Hemodynamic support in anaphylaxis and shock

›Antibiotics restraint

›Venom injury not equal infection

›Targeted antibiotics when infection signs present

›Avoidance of harmful field practices

›Tourniquets and incisions increase complications

›Ice and heat extremes worsen local injury in some bites

11Patient Discharge Instructions/pdi18

copy discharge instructions

›Discharge instructions

›Wound and limb care

›Keep limb elevated when resting

›Gentle range of motion as tolerated after pain improves

›Medications

›Use prescribed pain medicine as directed

›Avoid NSAIDs if told bleeding risk is present

›Return to ED now

›Trouble breathing

›Lip tongue face swelling

›Fainting or severe dizziness

›Rapidly increasing swelling spreading up the limb

›New numbness weakness or severe pain

›Bleeding from gums urine stool or from the bite site

›Fever with worsening redness or pus

›Follow up plan

›Recheck visit for worsening swelling or pain within 24 hours

›Lab recheck for snakebite related coagulopathy when advised

12References/r13

Key sources for local protocol alignment

›Clinical references

›Regional poison center guidance for antivenom selection and dosing

›Species specific antivenom protocols

›Delayed coagulopathy follow up recommendations

›Emergency medicine toxicology texts for envenomation syndromes

›Snakebite severity and antivenom response monitoring

›Latrodectism and loxoscelism supportive care

›Anaphylaxis consensus criteria and emergency treatment pathways

›IM epinephrine first line

›Observation guidance for biphasic reactions

›Source file

›Formatting and structural requirements applied

›Checkbox only database oriented output requirements applied

Evidence & Review

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

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.