T63.2
DESCRIPTION
Some scorpion species can cause serious systemic toxicity.
Thick-tailed scorpions with small pincers are extremely toxic, resulting in both local and systemic features. Thin-tailed scorpions with large pincers are much less toxic and usually cause local symptoms only.
DIAGNOSTIC CRITERIA
- Pain and paraesthesia occur immediately after envenomation.
- Autonomic and motor findings may differentiate scorpion bites from other causes of pain.
- The pain can be exquisitely accentuated by tapping on the affected region, i.e. “tap test”.
- In severe cases cranial nerve dysfunction, blurred vision, pharyngeal muscle incoordination, drooling and respiratory compromise can occur.
- Excessive motor activity may present as restlessness, or uncontrollable jerking of extremities.
- Other serious effects include cardiac dysfunction, pulmonary oedema, pancreatitis, bleeding disorders and skin necrosis.
- Nausea, vomiting, tachycardia and severe agitation can also occur.
GENERAL AND SUPPORTIVE MEASURES
- General supportive care.
- Monitor airway, breathing and circulation.
MEDICINE TREATMENT
For muscle cramps:
- Calcium gluconate 10%, IV, 0.5 mL/kg by slow intravenous injection.
- Give 0.5–1 mL/minute.
- Monitor ECG.
For pain:
- Paracetamol, oral, 15 mg/kg/dose, 6 hourly as required.
Very painful scorpion stings
- Lidocaine (lignocaine) 2%, 2 mL injected around the bite as a local anaesthetic.
If not immunised in the past 5 years:
- Tetanus toxoid, IM, 0.5 mL.
Complete course in previously unvaccinated patients.
Antivenom therapy
Antivenom therapy is recommended only in cases with systemic signs and is rarely required:
- Scorpion antivenom, slow IV, 10 mL administered over 3–5 minutes.
REFERRAL
- Severe cases requiring intensive care.