Emergency Flowchart

Signs and symptoms¹	Emergency medical treatment	Region	Possible culprit	Antivenom³


Autonomic nervous system Within hours: Transient cholinergic effects Vomiting, increased peristalsis, diarrhoea, abdominal pain; profuse sweating; pupil constriction. Priapism. Bradycardia, arterial hypotension, shock. Hypersalivation; increased bronchial secretion, bronchospasm, respiratory failure. Longer-lasting adrenergic effects Pupil dilatation. Tachycardia, arrhythmias, arterial hypertension, myocardial failure, pulmonary oedema (cardiogenic + ?non-cardiogenic component), cardiac ischaemia, shock. Hyperglycaemia (most likely due to hypercatecholaminaemia) Acute pancreatitis (also associated with hyperglycaemia) Hypertensive encephalopathy. Neuromuscular dysfunction Cranial nerves: Ptosis, "wandering" eye movements, dysphagia (inhalation of vomitus!), dysarthria, pharyngeal reflex absent; Skeletal musculature: Involuntary movements, restlessness, reduced grip and pinch strength; muscle spasms. Descending flaccid paralysis (rarely progresses to involve respiratory muscles) Cyanosis, shallow breathing, respiratory arrest (respiratory paralysis); respiratory arrest may be precipitated by obstruction of the upper airway, by the paralysed tongue or inhaled vomitus. Loss of consciousness and generalized convulsions caused by hypoxaemia in patients who have respiratory paralysis. Additional effects²	Species-specific envenoming patterns and clinical management in Clinical entries: Scorpions	India	Hottentotta thamulus	'Antivenom' in Clinical entries: Scorpions
		North Africa, Middle East	Androctonus sp. Buthus sp. Hemiscorpius lepturus Leiurus quinquestriatus Nebo hierochonticus
		Brazil, Trinidad	Tityus sp.
		Mexico, Southern USA	Centruroides sp.
		Southern Africa	Parabuthus sp.

Local pain is the dominant symptom, often severe, Redness; oedema; numbness. Tender local (spreading) swelling, Blistering, Lymphangiopathy and lymphadenopathy, Necrotic soft tissue; can include muscle locally.	Infiltration with local anaesthetic (xylocaine 1%, max. 0.5 ml, without the addition of a vasoconstrictor); regional nerve block anaesthesia	Numerous regions throughout the world	All scorpions

See also the Clinical flowchart as a guide to the dynamics of envenoming.

Additional effects:

Clotting disturbances (Nebo hierochonticus)
Localizing neurological signs, meningism, coma (intracranial bleeding!)
Systemic bleeding: retinal haemorrhages; cranial CT features of cerebellar and cerebral and cerebellar haemorrhages.

Microangiopathic haemolysis (Hemiscorpius lepturus)
Severe microangiopathic haemolysis causing early haemoglobinuria and leading to a HUS-like presentation with AKI that requiresrenal replacement therapy (Warrell 2023).

Early antivenom treatment is recommended, however, supportive evidence is poor (Amr et al 2021; Wilkins et al 2025, Warrell 2023).
Two systematic reviews and metanalyses performed in 2011 and 2017 found only for Centruroides spp in Mexico and USA (Boyer et al 2009) and Hottentotta tamulus in India (more rapid resolution than prazosin alone; Natu et al 2010; Bawaskar and Bawaskar 2011) limited evidence of faster resolution of signs and symptoms of envenoming (Abrough et al 2011; Rodrigo et al 2017).
In a trial in Tunesia (patients likely to have been stung by Androctonus australis or Buthus occitanus) antivenom did not show a benefit. However, only 18% of patients were envenomed (Abrough et al 1999; Amr et al 2021).

Indication and selection of antivenom needs to be based on the evidence available in the respective region where the envenoming occurs.