Scorpion Sting and its Treatment

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Scorpion Sting and its Treatment:

a) Buthus tamulus Scorpion Sting: Symptoms of vegetative stimulation during envenomation with Buthus tamulus venom in India include varying intensity of pain at the sting site, local swelling, cooling of the extremities, hives, vomiting, profuse and diffuse sweating, priapism, drooling, hypertension, brady- and tachyarrhythmias, ventricular extrasystoles. Early electrocardiographic changes include pointed T waves in leads V2-V6, Q waves, ST segment elevation in leads I and AVL, as well as left anterior fascicular block. Within 2-3 hours after the sting, pulmonary edema may develop, with death occurring within 3-4 hours.

b) Leiurus quinquestriatus Scorpion Sting: Scorpion stings by Leiurus quinquestriatus in tropics and subtropics have been associated with bradycardia, tachycardia, and hypertension in children, with less common occurrences of heart failure and pulmonary edema. Among adolescents and adults, abdominal pain, nausea, and vomiting seem to be more prevalent, likely due to acute pancreatitis. Perioral paresthesia has also been described following envenomation by this scorpion.

Treatment of Scorpion Stings:

Gueron and Sofer in Israel proposed the following intensive therapy scheme for intoxications caused by scorpion stings:

  1. Fluid loss due to vomiting, sweating, and drooling complicates the clinical picture, so correcting fluid imbalance is crucial to prevent worsening hemodynamic abnormalities and death.
  2. Respiratory insufficiency with or without CNS disturbances in the presence of hypertension or pulmonary edema should be aggressively managed, including early mechanical ventilation, reducing myocardial afterload, cautious sedation, and restoring acid-base balance.
  3. Cardiac rhythm and conduction disturbances may occur in the early hours after the sting, sometimes alongside pulmonary edema. These anomalies are usually transient and do not typically require specific treatment, except for tachyarrhythmias exacerbating hemodynamic instability.
  4. The mechanism of shock syndrome, i.e., severe hypotension, is unclear due to the lack of hemodynamic or non-invasive data. Antitoxin is ineffective, so all efforts should focus on supportive care, correcting hypovolemia, and possibly invasive monitoring if severe hypotension is accompanied by pulmonary edema, CNS and respiratory dysfunction.
  5. Patients with pulmonary edema, with or without hypertension, should receive treatment aimed at reducing myocardial afterload without compromising preload. Inotropic agents such as digitalis preparations are ineffective, and the routine use of diuretics without proper volume control in hypovolemia can be dangerous.
  6. Sometimes, there is a parasympathetic effect of the venom, rarely predominant in the clinical picture. In such situations, complete elimination of parasympathetic effects should be avoided, as it would lead to dominance of the overstimulated sympathetic system.
  7. Frequent non-invasive monitoring of left ventricular systolic and diastolic function is useful in the treatment of scorpion venom intoxications.

Treatment of severe scorpion venom intoxication should aim to neutralize the overstimulated autonomic nervous system. All patients with systemic symptoms, such as severe hypertension, hypovolemia, pulmonary edema, or shock, should be hospitalized in an intensive care unit equipped with facilities for electrocardiographic, echocardiographic, and, if necessary, invasive hemodynamic monitoring. Sedatives, fluid replacement, and reduction of afterload are prescribed. Mechanical ventilation is necessary for respiratory insufficiency or CNS dysfunction. Correction of acid-base imbalance is essential. Atropine, calcium-containing anti-inflammatory agents, and steroids are contraindicated. Antitoxin is ineffective, although there is disagreement regarding its relative value.

Cardiovascular and Vascular Manifestations:

  • Scorpion venom appears to stimulate the central and autonomic nervous systems and increases levels of catecholamines, renin, and aldosterone in the blood.
  • Treatment of cardiovascular anomalies should include cardiac monitoring, correction of fluid deficit and gas exchange, as well as rational use of calcium channel blockers, angiotensin-converting enzyme inhibitors, and vasodilators. Topical anticholinergics, such as atropine, may be applied when necessary.
  • Based on accumulated experience, treatment should aim to remove the excessive stimulation of the sympathetic nervous system rather than specifically neutralize the venom.

Excitement:

  • Intravenous phenobarbital (5-10 mg/kg) can alleviate neurological symptoms such as excitement and hyperactivity, but it is unlikely to reduce their duration. High doses of phenobarbital may lead to respiratory depression and may have contributed to increased mortality and worsening condition observed in early studies.
  • There is no rational basis for using antihistamines, corticosteroids, or calcium in the treatment of non-allergic reactions to scorpion stings.

Buthulus tamulus:

  • Hospitalization in the intensive care unit is recommended in India for those stung by Buthulus tamulus scorpions, along with oral nifedipine to lower blood pressure and alpha-blockers (prazosin hydrochloride) to suppress the peripheral effect of the venom. Digoxin, aminophylline, oxygen, diuretics, and sodium nitroprusside may be administered as needed. Some experts do not use antivenom.

Leiurus Quinquestriatus:

  • Continuous heart monitoring is necessary as long as symptoms persist. Respiratory failure may require mechanical ventilation. Excessive fluid administration may lead to pulmonary congestion. Calcium antagonists and vasodilators may be useful for reducing blood pressure. Hydralazine and nifedipine have shown effectiveness.

Antivenom against Scorpion Venom:

  • Most individuals who benefited from antivenom against scorpion venom (with disappearance of neurological, respiratory, cardiac, and vascular symptoms within 1-3 hours) may develop a rash or hives for the next 2 weeks. The antivenom is believed to reduce the duration of respiratory failure and may prevent acute necrosis of skeletal muscles. However, its use carries the risk of immediate anaphylaxis or delayed-type allergic reaction, so it should be used only in cases of severe symptoms. The effectiveness of antivenom against scorpion venom varies from country to country.

Prevention of Scorpion Stings:

  1. Avoiding contact with scorpions in their inhabited areas as much as possible.
  2. If a scorpion is found, it is usually not alone. The female can give birth to up to 60 offspring that stay close to where they were born. For safety reasons, if relocation is undesirable, all insects should be killed.
  3. Before wearing shoes, clothing, or changing bedding, they should be carefully inspected where scorpions may hide.
  4. Before placing any unprotected part of the body anywhere, the area should be thoroughly examined.
  5. Residential areas should be kept clean of garbage.
  6. Spraying pesticides is effective. A mixture of 2% chlorine, 10% DDT, and 0.2% pyrethrins in oil is used. This mixture is sprayed on building foundations and roofs. A less effective mixture includes mazut, kerosene, and a small amount of creosote.