Scorpion Envenomation
Description General measures Medicine treatment T63.2 + (X22.99/W59.99) DESCRIPTION Medically important scorpions in Southern Africa are of the genus Parabuthus ( P. granulatus and P. transvaalicus ). These are large scorpions measuring 7–15 cm in length. Features useful in their identification are a relatively large tail and small pincers, so-called thick-tailed scorpions. Scorpions from the Sco
T63.2 + (X22.99/W59.99)
DESCRIPTION
Medically important scorpions in Southern Africa are of the genus Parabuthus (P. granulatus and P. transvaalicus). These are large scorpions measuring 7–15 cm in length. Features useful in their identification are a relatively large tail and small pincers, so-called thick-tailed scorpions. Scorpions from the Scorpionidae family (e.g. Hadogenes, Opistophthalmus) are thin-tailed with large pincers.
To view pictures for the identification of scorpions:
http://www.cmej.org.za/index.php/cmej/article/view/2545/2580
A sting from thin-tailed scorpions is likely to result in local pain requiring analgesia only.
Clinical features of thick-tailed scorpion stings include:
Local effects:
- immediate and excruciating pain
- local paraesthesias and hyperaesthesia
Systemic effects:
- tremors, involuntary movements and fasciculations
- muscle pain, cramps, and weakness,
- generalised paraesthesias and hyperaesthesia
- excessive sympathetic stimulation e.g. sweating, tachycardia
- excessive parasympathetic stimulation e.g. hypersalivation, vomiting and diarrhoea, priapism
- bulbar paralysis (dysphagia, dysarthria)
- respiratory difficulty/failure
GENERAL MEASURES
- Observe all cases of thick-tailed scorpion stings for at least 12 hours.
- Monitor respiratory function.
- Ventilatory support may be required.
MEDICINE TREATMENT
Scorpion antivenom therapy is recommended only in cases presenting with systemic neurotoxic effects.
Antivenom available from South African Vaccine Producers (refer to the table above for contact details). See full details in the package insert.
- Scorpion antivenom, IV infusion, 10 mL diluted in 100 mL sodium chloride 0.9% or dextrose 5%, administered over 10 minutes.
- Response to antivenom may be slow and a repeat dose may be needed.
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CAUTION
Never administer antivenom without being prepared to manage acute anaphylaxis.
Immunisation, primary or booster:
(Z23.5)
- Tetanus toxoid vaccine, IM, 0.5 mL, immediately, if not previously immunised within the last 5 years.
In unimmunised or partially immunised patients:
(Z23.5)
- Tetanus immunoglobulin, human, IM, 250 units immediately.
Analgesia
For mild pain:
- Paracetamol, oral, 500mg to 1 g 4–6 hourly when required (to a maximum of 4 g in 24 hours)
- Maximum dose: 15 mg/kg/dose.
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Severe local pain:
Application of ice, if tolerated.
- Lidocaine 1–2%, 2 mL: infiltrate affected area as a local anaesthetic
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CAUTION
Opiates increase the risk of respiratory depression and if required, should only be used with caution in severe uncontrolled pain.
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Severe muscle pain and cramps:
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- Calcium gluconate 10%, bolus IV infusion, 10 mL over 10 minutes.
- Repeat if needed, only once i.e. maximum recommended dose of 2 grams.
Note:
Effect may only last for 20–30 minutes and there is a limited amount that can be given.
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Standard Treatment Guidelines and Essential Medicines List for South Africa, Adult Hospital Level, 2020-2024_Version 2.0_27 March 2025
Chapter 19 Poisoning_19.3 Scorpion Envenomation