Snake Bite: Types and Clinical Features
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Snake Bite in Pediatric Emergency: Introduction
Key Points
- Snake bites account for significant pediatric morbidity and mortality worldwide
- Children are at higher risk due to their smaller body mass and tendency for outdoor play
- Time to treatment is crucial - early identification of snake type guides specific management
- Clinical features vary based on the type of venom and time since bite
General Clinical Features
Initial Presentation:
- Fang marks (may be single, double, or multiple)
- Local pain and swelling
- Anxiety and fear response
- Time since bite critically important
- History of snake appearance if available
Neurotoxic Snake Bites
Common Species
- Cobra (Naja species)
- Krait (Bungarus species)
- Mamba (Dendroaspis species)
Clinical Features
- Early Signs (0-30 minutes):
- Paresthesias around the mouth
- Metallic taste
- Excessive salivation
- Ptosis (earliest sign)
- Progressive Signs (30 minutes - 6 hours):
- External ophthalmoplegia
- Facial muscle weakness
- Bulbar palsy
- Descending paralysis
- Respiratory muscle weakness
- Late Signs (6+ hours):
- Complete paralysis
- Respiratory failure
- Fixed dilated pupils
Distinguishing Features
- Minimal local swelling
- Rapid onset of neurological symptoms
- Clear progression of paralysis
- No coagulopathy
Hemotoxic Snake Bites
Common Species
- Vipers (Viperidae family)
- Rattlesnakes (Crotalus species)
- Russell's viper (Daboia russelii)
Clinical Features
- Early Signs (0-2 hours):
- Immediate severe pain
- Progressive swelling
- Ecchymosis
- Bleeding from bite site
- Progressive Signs (2-12 hours):
- Systemic bleeding manifestations
- Gingival bleeding
- Epistaxis
- Hematemesis
- Hematuria
- Laboratory Findings:
- Prolonged clotting time
- Thrombocytopenia
- Elevated D-dimer
- Decreased fibrinogen
Distinguishing Features
- Prominent local swelling
- Active bleeding manifestations
- Coagulopathy on lab tests
- Risk of compartment syndrome
Cytotoxic Snake Bites
Common Species
- Puff adder (Bitis species)
- Some cobras (Naja species)
- African spitting cobras
Clinical Features
- Early Signs (0-6 hours):
- Severe local pain
- Rapid tissue swelling
- Blistering
- Bruising
- Progressive Signs (6-24 hours):
- Tissue necrosis
- Compartment syndrome
- Skin discoloration
- Regional lymphadenopathy
- Late Complications:
- Deep tissue necrosis
- Tissue sloughing
- Secondary infection
- Permanent tissue damage
Distinguishing Features
- Predominant local tissue destruction
- Progressive necrosis
- Minimal systemic symptoms
- Risk of permanent tissue damage
Myotoxic Snake Bites
Common Species
- Sea snakes
- Some Australian elapids
- Some kraits
Clinical Features
- Early Signs (0-2 hours):
- Minimal local symptoms
- Generalized muscle pain
- Muscle tenderness
- Progressive Signs (2-12 hours):
- Generalized myalgia
- Muscle weakness
- Trismus
- Dark colored urine
- Laboratory Findings:
- Elevated CPK
- Myoglobinuria
- Hyperkalemia
- Acute kidney injury
Distinguishing Features
- Minimal local symptoms
- Predominant muscle involvement
- Risk of rhabdomyolysis
- Risk of renal failure
Mixed Toxicity Snake Bites
Common Species
- Eastern brown snake
- Tiger snake
- Some vipers
Clinical Features
- Combination of:
- Neurotoxic features
- Coagulopathy
- Local tissue damage
- Myotoxicity
- Complex Presentation:
- Variable onset of symptoms
- Multiple organ involvement
- Unpredictable progression
Initial Assessment Guidelines
Primary Survey
- Airway:
- Assess for swelling/obstruction
- Check for bulbar involvement
- Monitor respiratory effort
- Breathing:
- Respiratory rate and effort
- Oxygen saturation
- Signs of respiratory paralysis
- Circulation:
- Blood pressure monitoring
- Capillary refill time
- Bleeding manifestations
Documentation Requirements
- Time of bite
- Site of bite
- First aid measures taken
- Progress of local swelling
- Serial neurological examinations
- Vital signs trending
