What is the treatment for scorpion poisoning?

Treatment for Scorpion Poisoning

The definitive treatment for scorpion poisoning is ANASCORP® [centruroides (scorpion) immune F(ab')2 (equine) injection], which should be administered as soon as possible after a scorpion sting in patients who develop clinically important signs of envenomation. 1

Clinical Presentation and Assessment

Clinically important signs of scorpion envenomation include:

• Loss of muscle control
• Roving or abnormal eye movements
• Slurred speech
• Respiratory distress
• Excessive salivation
• Frothing at the mouth
• Vomiting

Severity Classification

• Mild: Local pain and paresthesia
• Moderate: Pain and paresthesia remote from sting site
• Severe: Cranial nerve dysfunction, somatic skeletal neuromuscular dysfunction, or both

Treatment Protocol

1. Immediate Management

• Antivenom Administration (ANASCORP) 1

  • Initial dose: 3 vials reconstituted with 5 mL sterile normal saline each
  • Combine and dilute to total volume of 50 mL with sterile normal saline
  • Infuse intravenously over 10 minutes
  • Monitor patient closely during and up to 60 minutes following infusion

• Additional dosing 1

  • If clinically important signs persist, administer additional vials
  • One vial at a time at 30-60 minute intervals
  • Reconstitute and dilute as with initial dose
  • Continue until resolution of symptoms

2. Supportive Care

• Cardiovascular Support 2

  • For myocarditis and cardiogenic shock:
    • Dobutamine for inotropic support
    • Monitor cardiac function

• Respiratory Support 2

  • For acute pulmonary edema:
    • Oxygen supplementation
    • Ventilatory support if needed
    • Consider sodium nitroprusside for severe hypertension

• Pharmacological Adjuncts 3, 4

  • Prazosin: 30 mcg/kg/dose every 6 hours until recovery
    • Particularly effective in antagonizing the toxicological effects of scorpion venom
    • Helps manage hypertension and pulmonary edema

3. Monitoring and Follow-up

• Continuous cardiac monitoring in intensive care setting 5
• Monitor for delayed allergic reactions (serum sickness) 1
  • Symptoms include rash, fever, myalgia, arthralgia
  • Occurs in approximately 0.5% of patients

Special Considerations

Hypersensitivity Reactions

• Be prepared for potential severe hypersensitivity reactions, including anaphylaxis 1
• Have emergency medications ready:
  • Epinephrine
  • Corticosteroids
  • Diphenhydramine

Pediatric Patients

• Children are at higher risk for severe envenomation and mortality 5
• Aggressive management is critical, especially for:
  • Acute pulmonary edema
  • Encephalopathy
  • Myocarditis

Pitfalls and Caveats

1. Delayed Treatment: Patients brought to medical care after longer time intervals have significantly worse outcomes 5

2. Inappropriate Initial Management: Avoid administering steroids and antihistamines as primary treatment, as they have been associated with higher mortality 4

3. Underestimating Severity: Scorpion envenomation can rapidly progress from seemingly mild symptoms to life-threatening conditions 2

4. Insufficient Monitoring: Even after apparent clinical improvement, patients should be observed for at least 24 hours due to risk of delayed complications 4

5. Overlooking Inflammation: Beyond neurotoxic effects, scorpion venom induces a complex hyperinflammatory state similar to systemic inflammatory response syndrome 6

The treatment approach should focus on early antivenom administration with ANASCORP, appropriate supportive care including prazosin and cardiac support when needed, and careful monitoring in an intensive care setting for at least 24 hours.