SCORPION STING (لدغة العقرب)
Comprehensive Clinical Guide
1. Pathophysiology of Scorpion Venom
Scorpion venom contains neurotoxins that block ion channels (K+, Na+, Ca2+), causing prolonged nerve firing and hormonal imbalances leading to:
- Decreased insulin secretion
- Increased catecholamines (ischemia, arrhythmias)
- Elevated angiotensin II (vasoconstriction)
2. Scorpion Venom Effects
A. Neurotoxic (Autonomic Storm)
Parasympathetic: Hypothermia, Bradycardia, Hypotension, Bronchospasm, Salivation, Priapism.
Sympathetic: Hyperthermia, Tachycardia, Hypertension, Arrhythmia, Pulmonary edema, Seizure, Profuse sweating.
Treatment: Prazosin (برازوسين) can be used for sympathetic effects.
B. Local Effects
- Sharp, burning pain
- Mild redness / swelling
- No fang marks (لاتوجد آثار أنياب)
3. Clinical Assessment & Grading
| Grade | Presentation | Treatment Protocol |
|---|---|---|
| Grade 0 | No local or systemic signs. | 6h observation. |
| Grade 1 | Local burning pain, paresthesia. | Antivenom 3 ampoules, Local xylocaine. |
| Grade 2 | Local signs spreading to distant sites. | Same as Grade 1, close monitoring. |
| Grade 3 | Local + Systemic signs. | Antivenom 5 ampoules, repeat hourly. |
| Grade 4 | Grade 3 + Shock + Pulmonary edema. | ICU admission. Lasix, Oxygen. |
4. Medication Guidance
A. Indicated Medications
- Scorpion Antivenom: According to clinical grade and severity.
- Prazosin: For autonomic storm and sympathetic overactivity.
- Oxygen therapy: In respiratory distress or pulmonary edema.
- Diuretics (Lasix): In pulmonary edema.
- Local anesthetics (Xylocaine): For severe local pain.
- ICU supportive care: In Grade 4 envenomation.
B. Contraindicated Medications
- Beta blockers: May worsen unopposed alpha-adrenergic activity.
- ACE inhibitors: Can aggravate hypotension.
- Morphine: Risk of respiratory depression and hypotension.
- Steroids: No proven benefit in scorpion envenomation.
- Digoxin: Increased risk of arrhythmias.
