Scorpion Sting

The toxicity of scorpion venom surpasses that of snakes, although the quantity injected is relatively small.

Scorpion venom is composed of a mixture of various active substances, including polypeptides and enzymes.

It is crucial not to underestimate the severity of any scorpion sting, regardless of the species involved, and it is recommended to observe the patient for 24 hours.

Incision at the sting site or applying a tourniquet is strongly discouraged. Patients suspected of being envenomated should be hospitalized for a minimum of 12 hours and closely monitored for cardiovascular and neurological complications.

The venom comprises neurotoxins, hemolysins, agglutinins, hemorrhagins, leukocytolysins, coagulins, lecithin, cholesterol, cardiotoxins, nephrotoxins, and hyaluronidases.

Based on the clinical manifestations, scorpion envenomation is categorized into four grades:

Grade 1 (0-2 hours after the incident):

Severe, excruciating local pain radiating along corresponding dermatomes.

Mild local edema at the sting site without systemic involvement.

Management:

Nonsteroidal anti-inflammatory drugs (NSAIDs).

Lignocaine/symptomatic treatment.

Grade 2:

Autonomic storm symptoms characterized by parasympathetic and sympathetic stimulation.

Increasingly intense local pain.

Arterial hypotension alternating with hypertensive crisis (systolic 20-30 mmHg above normal).

Management:

Administration of Tab Prazocin 1mg stat (30mcg/kg in children).

Grade 3:

Cold extremities.

Tachycardia.

Hypotension or hypertension.

Cardiogenic shock with pulmonary edema.

Management:

Oxygen inhalation.

Positive pressure ventilation (PPV).

Intravenous fluids.

Dobutamine.

Prazocin.

Nitroprusside/NTG.

Grade 4:

Tachycardia.

Hypotension with or without pulmonary edema.

Warm extremities (warm shock).

Management:

Oxygen inhalation.

Positive pressure ventilation (PPV).

Intravenous fluids.

Dobutamine.

Prazocin.

Prazocin is a pharmacological and physiological antidote to the effects of scorpion venom, acting as a competitive postsynaptic alpha-1 adrenoreceptor antagonist.

If the patient is vomiting, prazosin should be administered through a nasogastric tube, and the patient should maintain a lying posture for approximately 3 hours, even during examination, to prevent "first dose hypotension phenomenon."

Prazosin can be repeated in the same dose after 3 hours based on clinical response, and subsequently administered every 6 hours (not exceeding a total of 5 mg per day) until the extremities are warm, dry, and peripheral veins are easily visible.

Prazosin can be administered regardless of blood pressure, provided there is no hypovolemia.

Since the introduction of prazosin, the fatality rate from scorpion stings has been reduced to less than 1%.

Prazosin serves as a cellular and pharmacologic antidote to the effects of scorpion venom, and it also has cardioprotective properties.

It should be considered the primary treatment option for severe scorpion stings and is often referred to as an affordable alternative to scorpion antivenom.

The time elapsed between the sting and the administration of prazosin for autonomic storm symptoms significantly influences the outcome.