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SCORPIONS, MESOBUTHUS TAMULUS

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Classification   |    Detailed evidence-based information

Substances Included Synonyms

Therapeutic Toxic Class

    A) Scorpions are members of the order Scorpionida, and are the most primitive and oldest members of the terrestrial arachnids.
    B) Out of approximately 20 different species of the genus mesobuthus (or buthotus), only mesobuthus tamulus is known to cause clinically significant envenomation in humans.

Specific Substances

    1) Buthotus
    2) Buthotus tamulus
    3) Indian red scorpion
    4) Mesobuthus
    5) Mesobuthus tamulus

Available Forms Sources

    A) SOURCES
    1) Scorpion stings can occur year round in tropical and temperate climates. Stings commonly occur in the home when scorpions enter dwellings and hide in clothing, bedding and shoes.

Overview

Life Support

    A) This overview assumes that basic life support measures have been instituted.

Clinical Effects

    0.2.1) SUMMARY OF EXPOSURE
    A) BACKGROUND: Scorpions are terrestrial arachnids of the order Scorpionida. They are nocturnal, and during the day they seek protection by hiding under stones or bark or in wood piles. They may also live in and around human dwellings. Out of approximately 20 different species of the genus Mesobuthus (or Bothotus), only Mesobuthus tamulus (also known as Indian red scorpion) is known to cause clinically significant envenomation in humans. The Mesobuthus tamulus scorpion is the most lethal among the Buthedae family. It is a small scorpion, up to 10 cm in length, with color ranging from yellow to brownish to black. It is distributed throughout the Indian subcontinent.
    B) TOXICOLOGY: Scorpion venom activates sodium channels, causing increased neurotransmitter release. This can result in cholinergic manifestations (ie, vomiting, sweating, priapism, hypersalivation) followed by sustained adrenergic excess secondary to catecholamine release (ie, hypertension, tachycardia, myocardial failure, pulmonary edema). A number of toxins have been isolated from the Mesobuthus tamulus venom and include Iberiotoxin (a high conductance calcium activated potassium channel blocker) and PoTx (a high molecular weight polypeptide pulmonary edema producing toxin) which are both considered lethal. The mechanism of these toxins are different, which can result in various signs and symptoms of toxicity.
    C) EPIDEMIOLOGY: Mesobuthus tamulus is distributed throughout the Indian subcontinent.
    D) WITH POISONING/EXPOSURE
    1) MILD ENVENOMATION: Patients with mild envenomation may develop only pain at the site of envenomation, with radiation up the involved extremity. Common systemic manifestations of envenomation include diaphoresis, nausea, vomiting, salivation, facial swelling and miosis.
    2) SEVERE ENVENOMATION: Severe signs of envenomation include hypertension, tachycardia, hypotension, myocardial failure, pulmonary edema, encephalopathy, dysrhythmias, and priapism. Cerebellar infarcts are extremely rare. Though miosis has been reported as a cholinergic effect, mydriasis has also been described. Hypertension develops in most patients with moderate to severe envenomations while hypotension is mostly in those with severe envenomations. Those with hypotension often develop pulmonary edema. A variety of electrocardiogram changes have been described with envenomation, including ST segment depression, tall T waves, ST elevation, fascicular block QRS widening, and low voltage. In severe envenomation, myocarditis may develop with manifestations of pulmonary edema and/or hypotension. There have been case reports of cerebellar infarctions and one case report of intracerebral hemorrhage, which was felt to be secondary to hypertension. Children have developed symptoms of encephalopathy after poisoning. The actual sting site usually has an unremarkable appearance, although mild swelling, small punctuate hemorrhages, localized sweating, and blackish discoloration have been reported at the site.
    0.2.5) CARDIOVASCULAR
    A) WITH POISONING/EXPOSURE
    1) Life threatening cardiac toxicity may develop with severe envenomation. Tachycardia is common, and may be quite severe. Hypertension is also quite common, often associated with clinical evidence of vasoconstriction. Patients with severe envenomation may develop left ventricular dysfunction with hypotension and/or pulmonary edema.

Laboratory Monitoring

    A) Monitor vital signs frequently.
    B) Those with systemic signs of intoxication should have serial ECGs and continuous cardiac monitoring with pulse oximetry. In addition, monitor serum electrolytes, renal function, hepatic enzymes, and labs to assess myocardial injury.
    C) Patients with dyspnea, hypoxia or evidence of pulmonary edema should have a chest radiograph.
    D) There is no specific laboratory study for scorpion toxins that is clinically useful.
    E) Laboratory studies should be targeted towards patient symptoms, and patients with mild symptoms may not need any specific studies.

Treatment Overview

    0.4.7) BITES/STINGS
    A) MANAGEMENT OF MILD TO MODERATE TOXICITY
    1) Most of the case series evaluating treatments for Mesobuthus tamulus envenomation come from areas of India where access to intensive medical care is limited. There are few designed studies evaluating the efficacy of any treatment. Basic first aid should be applied to all patients. Keep the patient calm and transport to a medical facility. Immobilize the affected part in a functional position. Apply cold packs to the sting site but do not apply ice directly to the skin (to prevent further skin injury). There is no evidence for the utility of suction devices or constriction bandages. Do not apply any type of tourniquet. To treat pain, infiltration of the sting site with local anesthetic may be helpful. Other pain medications such as nonsteroidal anti-inflammatories, acetaminophen or opioids may also help.
    B) MANAGEMENT OF SEVERE TOXICITY
    1) HYPERTENSION: Hypertension has been treated with oral prazosin where intensive care is limited. ADULT: One reported regimen is 500 mcg/dose repeated every 3 to 4 hours and then every 6 hours as needed for usually up to 24 hours; PEDIATRIC: 250 mcg/dose every 3 to 4 hours and then every 6 hours as needed for usually up to 24 hours. As an alphablocker, prazosin acts by reversing vasoconstriction induced by catecholamine discharge. Phentolamine, an alphablocker, may also be useful but has not been studied for scorpion envenomations. Typical doses of phentolamine for adults is 5 to 15 mg IV bolus and 0.05 to 0.1 mg/kg/dose (maximum of 5 mg/dose) IV every 5 minutes as needed for children.
    a) PULMONARY EDEMA/HYPERTENSION: Nitroprusside has been used to treat pulmonary edema and hypertension secondary to envenomation. ADULT: 0.1 mcg/kg/min initially with titration to the desired effect (up to 10 mcg/kg/min); PEDIATRIC: 0.5 mcg/kg/min with titration up to 8 mcg/kg/min.
    b) NITROGLYCERIN: Intravenous nitroglycerin can also be used as an alternative to control hypertension and heart failure. Infusion in adults begins at 10 to 20 mcg/min with an increase of 5 to 10 mcg/min every 5 to 10 minutes until the desired hemodynamic response is achieved. In children, the usual dose in those 29 days or older is 1 to 5 mcg/kg/min continuous IV infusion to a maximum of 60 mcg/kg/min.
    2) HYPOTENSION: Patients with severe hypotension may require intravenous fluids and pressors of choice. Captopril has been used in a small subgroup of patients with pulmonary edema and hypotension to reduce left ventricular afterload and improve right ventricular preload.
    3) MYOCARDITIS: L-carnitine, 1980 mg orally divided 3 times daily, has been used to treat myocarditis, but there are no controlled trials assessing its efficacy. It is postulated to preserve myocardial fatty acid metabolism, enhance oxidative glucose metabolism, increase ATP availability and improve myocardial function.
    C) DECONTAMINATION
    1) PREHOSPITAL: There is no role for ipecac or activated charcoal for scorpion stings. Local wound care is reasonable but will not directly treat the envenomation.
    2) HOSPITAL: There is no role for the use of activated charcoal, whole bowel irrigation, or gastric lavage for scorpion stings.
    D) AIRWAY MANAGEMENT
    1) Pulmonary edema may develop in severe cases of scorpion stings and may necessitate early intubation if respiratory status quickly worsens.
    E) ANTIDOTE
    1) Haffkine Biopharma located in Mumbai has manufactured a monovalent anti-scorpion venom serum F(ab)2 against Mesobuthus tamulus since 1997 that has been available for clinical use in rural areas since 2002. However, there are reports that it is frequently in short supply and may not be readily available.
    F) ENHANCED ELIMINATION
    1) There is no evidence for the use of dialysis, hemoperfusion, or urinary alkalinization.
    G) PATIENT DISPOSITION
    1) HOME CRITERIA: Home care is not indicated in any patient following a potential envenomation.
    2) OBSERVATION CRITERIA: Patients with symptoms that are worsening or systemic symptoms should be sent to a healthcare facility for observation and observed for 4 to 6 hours or until they are clearly improving. Criteria for discharge include patients who are medically stable and clearly improving.
    3) ADMISSION CRITERIA: Any patients with worsening symptoms or systemic symptoms that are worrisome (eg, causing abnormal vital signs) should be admitted to the hospital, and may necessitate an ICU admission if they develop severe symptoms such as pulmonary edema requiring vasopressor and/or intubation. Patients should not be discharged until they are clearly improving and medically stable.
    4) CONSULT CRITERIA: Depending on the severity of symptoms, an intensivist consultation may be needed for patients who develop pulmonary edema and require ICU care. A toxicologist or poison center may be involved at any time for advice and may help facilitate access to an antivenom.
    H) PITFALLS
    1) One potential pitfall may be the lack of recognition of the potential severity of symptoms. Another is that these scorpions may be kept as pets in areas where they are not endemic, and thus stings may potentially occur worldwide.
    I) PREDISPOSING CONDITIONS
    1) Children appear to develop more severe toxicity compared to adults.
    J) DIFFERENTIAL DIAGNOSIS
    1) Envenomation from other arthropods (eg, spiders, insects, other scorpion genera) may share some similar symptoms to Mesobuthus tamulus envenomations.

Range Of Toxicity

    A) A single sting can cause severe, even fatal envenomation. Children appear to develop more severe toxicity than adults.

Clinical Effects

Summary Of Exposure

    A) BACKGROUND: Scorpions are terrestrial arachnids of the order Scorpionida. They are nocturnal, and during the day they seek protection by hiding under stones or bark or in wood piles. They may also live in and around human dwellings. Out of approximately 20 different species of the genus Mesobuthus (or Bothotus), only Mesobuthus tamulus (also known as Indian red scorpion) is known to cause clinically significant envenomation in humans. The Mesobuthus tamulus scorpion is the most lethal among the Buthedae family. It is a small scorpion, up to 10 cm in length, with color ranging from yellow to brownish to black. It is distributed throughout the Indian subcontinent.
    B) TOXICOLOGY: Scorpion venom activates sodium channels, causing increased neurotransmitter release. This can result in cholinergic manifestations (ie, vomiting, sweating, priapism, hypersalivation) followed by sustained adrenergic excess secondary to catecholamine release (ie, hypertension, tachycardia, myocardial failure, pulmonary edema). A number of toxins have been isolated from the Mesobuthus tamulus venom and include Iberiotoxin (a high conductance calcium activated potassium channel blocker) and PoTx (a high molecular weight polypeptide pulmonary edema producing toxin) which are both considered lethal. The mechanism of these toxins are different, which can result in various signs and symptoms of toxicity.
    C) EPIDEMIOLOGY: Mesobuthus tamulus is distributed throughout the Indian subcontinent.
    D) WITH POISONING/EXPOSURE
    1) MILD ENVENOMATION: Patients with mild envenomation may develop only pain at the site of envenomation, with radiation up the involved extremity. Common systemic manifestations of envenomation include diaphoresis, nausea, vomiting, salivation, facial swelling and miosis.
    2) SEVERE ENVENOMATION: Severe signs of envenomation include hypertension, tachycardia, hypotension, myocardial failure, pulmonary edema, encephalopathy, dysrhythmias, and priapism. Cerebellar infarcts are extremely rare. Though miosis has been reported as a cholinergic effect, mydriasis has also been described. Hypertension develops in most patients with moderate to severe envenomations while hypotension is mostly in those with severe envenomations. Those with hypotension often develop pulmonary edema. A variety of electrocardiogram changes have been described with envenomation, including ST segment depression, tall T waves, ST elevation, fascicular block QRS widening, and low voltage. In severe envenomation, myocarditis may develop with manifestations of pulmonary edema and/or hypotension. There have been case reports of cerebellar infarctions and one case report of intracerebral hemorrhage, which was felt to be secondary to hypertension. Children have developed symptoms of encephalopathy after poisoning. The actual sting site usually has an unremarkable appearance, although mild swelling, small punctuate hemorrhages, localized sweating, and blackish discoloration have been reported at the site.

Heent

    3.4.2) HEAD
    A) WITH POISONING/EXPOSURE
    1) Facial swelling has been described after Mesobuthus tamulus envenomation (Bawaskar & Bawaskar, 1996; Bawaskar & Bawaskar, 2000).
    3.4.3) EYES
    A) WITH POISONING/EXPOSURE
    1) Miosis has bee reported as a cholinergic effect (Bawaskar & Bawaskar, 1997).
    2) Mydriasis has also been described (Gaitonde et al, 1978).

Cardiovascular

    3.5.1) SUMMARY
    A) WITH POISONING/EXPOSURE
    1) Life threatening cardiac toxicity may develop with severe envenomation. Tachycardia is common, and may be quite severe. Hypertension is also quite common, often associated with clinical evidence of vasoconstriction. Patients with severe envenomation may develop left ventricular dysfunction with hypotension and/or pulmonary edema.
    3.5.2) CLINICAL EFFECTS
    A) HYPERTENSIVE EPISODE
    1) WITH POISONING/EXPOSURE
    a) Hypertension develops in most patients with moderate envenomation and many patients with severe envenomation, with incidences of 73% to 100% in a few small case series (Gadwalkar et al, 2006; Jain et al, 2006; Bawaskar & Bawaskar, 2000; Bawaskar & Bawaskar, 1996).
    b) A clinical presentation has been described after Mesobuthus tamulus envenomation, which consists of hypertension, which may be severe (BP up to 240/160 mmHg), normal or bradycardic pulse, dysrhythmias, ischemic ECG changes, systolic heart murmur, priapism, facial swelling, and sweating, salivation and vomiting leading to dehydration. An estimated 8.5% of these patients go on to develop pulmonary edema (Bawaskar & Bawaskar, 1997).
    B) HYPOTENSIVE EPISODE
    1) WITH POISONING/EXPOSURE
    a) Hypotension develops with severe envenomation, and these patients often develop pulmonary edema (Bawaskar & Bawaskar, 1997; Das et al, 1995; Karnad, 1998).
    C) TACHYARRHYTHMIA
    1) WITH POISONING/EXPOSURE
    a) Tachycardia develops in most patients with severe envenomation (Das et al, 1995; Bawaskar & Bawaskar, 1996).
    b) A clinical presentation has been described after Mesobuthus tamulus envenomation, which consists of tachycardia, sometimes severe (pulse rate 110 to 215 beats/minute), apical systolic murmur, and cold extremities. About 10% of these patients go on to develop pulmonary edema (Bawaskar & Bawaskar, 1997).
    D) MYOCARDIAL DYSFUNCTION
    1) WITH POISONING/EXPOSURE
    a) In a prospective observational study conducted in a tertiary-care center in Southern India from 2012 to 2014, children less than 13 years of age presenting with a scorpion sting envenomation or a bite consistent with a scorpion sting were enrolled in the study to identify the predictive risk factors for the development of myocardial dysfunction. Of the 85 children admitted with scorpion sting envenomation, 24 children were diagnosed with myocardial dysfunction. The diagnosis was based on the following criteria: congestive cardiac failure or cardiomegaly, hemodynamic compromise that required vasopressor therapy, left ventricular dysfunction, an elevated CPK-MB levels and an abnormal ECG. Multivariate analysis showed that a delay in hospital admission (greater than 4 hours) after a sting (OR (Odds Ratio) 13.8 (3.3 to 58.7), p <0.001), the presence of hypotension at the time of admission (OR 8.9 (3.4 to 36.8), p < 0.003), and treatment with prazosin without Scorpion antivenom (OR 2.8 (0.1 to 14.4), p <0.160) were predictors of myocardial dysfunction. The early administration (less than 4 hours) of Scorpion antivenom along with prazosin reduced the risk of myocardial dysfunction and prevented clinical deterioration of children that presented with grade 2 envenomation (Kumar et al, 2015).
    E) PULMONARY EDEMA
    1) WITH POISONING/EXPOSURE
    a) Pulmonary edema is common in patients with severe envenomation. A clinical presentation has been described after Mesobuthus tamulus envenomation, which consists of pulmonary edema, hypotension, weak thready pulse, cold cyanosed extremities, tachypnea, orthopnea, cough with hemoptysis or red frothy sputum, usually without priapism or sweating (cholinergic manifestations) (Bawaskar & Bawaskar, 1997; Das et al, 1995; Karnad, 1998).
    F) ELECTROCARDIOGRAM ABNORMAL
    1) WITH POISONING/EXPOSURE
    a) A variety of ECG changes have been described, including ST segment depression, tall T waves, ST elevation, fascicular block, QRS widening, and low voltage (Bawaskar & Bawaskar, 2000; Das et al, 1995; Bawaskar & Bawaskar, 1992; Bawaskar & Bawaskar, 1996; Santhanakrishnan et al, 1977).
    b) The ECG may suggest acute myocardial infarction (Bawaskar & Bawaskar, 1996).
    G) MYOCARDITIS
    1) WITH POISONING/EXPOSURE
    a) Myocarditis is common in patients with severe envenomation, usually manifested as pulmonary edema and/or hypotension (Jain et al, 2006; Karnad, 1998; Das et al, 1995; Bawaskar & Bawaskar, 1996).
    b) Echocardiography may reveal transient left ventricular dysfunction, global hypokinesia and/or dilated cardiomyopathy. The mean ejection fraction in 24 patients with myocarditis after scorpion sting was 25.5% (SD 12.8%). Echocardiogram usually returns to normal within several days to a few weeks (Rajasekhar & Mohan, 2004). Moderate mitral regurgitation may also develop (Jain et al, 2006).
    c) ECG manifestations include dysrhythmias, conduction disturbances and ST-T changes (Rajasekhar & Mohan, 2004). CK elevation is common in these patients (Rajasekhar & Mohan, 2004; Bawaskar & Bawaskar, 2003).
    d) Chest radiograph may show an increase in cardiac size. Physical exam findings suggestive of myocarditis include tachycardia, muffled heart sounds, gallop rhythm, or evidence of heart failure (Rajasekhar & Mohan, 2004).
    H) COLD EXTREMITIES
    1) WITH POISONING/EXPOSURE
    a) Cold extremities, increased capillary refill time, and other evidence of poor tissue perfusion may result from either intense vasoconstriction (usually associated with hypertension), severe tachycardia, or from left ventricular dysfunction (usually in conjunction with hypotension and/or pulmonary edema) (Jain et al, 2006; Bawaskar & Bawaskar, 1992; Das et al, 1995).
    I) BRADYCARDIA
    1) WITH POISONING/EXPOSURE
    a) Bradycardia occurs in a substantial number of patients early in the course of systemic venom effects. It is likely secondary to cholinergic effects. Bradycardia was reported on hospital presentation in 27 of 119 (22.7%) of patients with severe Mesobuthus tamulus stings in one study (Bawaskar & Bawaskar, 1996), and 2 out of 32 children (6.25%) in another study (Das et al, 1995).
    J) CARDIOMYOPATHY
    1) WITH POISONING/EXPOSURE
    a) Mesobuthus tamulus envenomation may be a risk factor for the development of cardiomyopathy later in life.
    b) STUDY: In a case control study of Indian patients with idiopathic cardiomyopathy, 33 of 45 cases had a history of scorpion envenomation, and in 12 of these the history suggested myocardial dysfunction at the time of the sting. In the first group of 90 controls (age and sex-matched in patients on the medical wards), 23 had a history of scorpion sting. In the second group of 45 controls (spouses or close relatives living with the cardiomyopathy patient), 11 had a history of scorpion sting.
    1) Odds ratio for a history of scorpion sting in patients with cardiomyopathy was 8.01 (95% CI 3.55 to 18.06) as compared with the first control group, and 8.33 (95% CI 6.55 to 10.59) as compared with the second control group (Sundararaman et al, 1999).

Neurologic

    3.7.2) CLINICAL EFFECTS
    A) CEREBROVASCULAR ACCIDENT
    1) WITH POISONING/EXPOSURE
    a) CASE REPORT: A 4-year-old boy was stung by a "red" scorpion on the right side of the neck. The following day he was unable to move his right arm or leg and was unable to speak. On presentation to the hospital 2 days after the sting he had right hemiparesis (strength 2/4), right upper motor neuron facial palsy, and unable to speak but could understand speech. CT scan, 12 days after admission, showed infarction involving the left caudate nucleus, anterior limb of the internal capsule, and lenticular nucleus. The hypodense areas extended superiorly into the middle cerebral artery territory with some spared area in between. Strength of the right limbs gradually improved to normal and the facial palsy improved but he did not speak during his 14 day hospital stay (Raichur et al, 2001).
    B) CEREBELLAR INFARCTION
    1) WITH POISONING/EXPOSURE
    a) SUMMARY: Cerebellar infarcts are considered extremely rare complication following a scorpion sting due to the vasculotoxic action of the venom. Three cases of cerebellar infarction have been reported, in two of the cases, the symptoms resolved completely within 15 days (Gadwalkar et al, 2006; Jain et al, 2006).
    b) CASE REPORTS: In separate cases, two young women (28 and 30 years old) were stung by a scorpion and developed neurologic symptoms, which included slurred speech, progressive incoordination leading to ataxia over 6 to 12 hours. Neither women had any risk factors for stroke. Neurologic exam included cerebellar type of dysarthria and cerebellar signs were present on both sides in each patient. Head CT also showed multiple bilateral cerebellar infarcts. Supportive care included mannitol and aspirin; antivenom was not available in either case. Both patients recovered completely within 15 days; a follow-up head CT in the 30-year-old woman showed no areas of infarction (Gadwalkar et al, 2006).
    c) CASE REPORT: A 35-year-old man was stung with a "brown-colored" scorpion and his extremities became cool and he developed mild right-sided hemiparesis, extensor plantar response and left-sided cerebellar signs. A head CT revealed multiple infarcts involving the cerebellar, parieto-occipital, and thalamic regions. One week after exposure, the patient had persistent right-sided hemiparesis, residual dysarthria, and left-sided cerebellar signs. The authors speculated that the clinical events were due to a hypoperfusion infarct secondary to systemic toxicity (Jain et al, 2006).
    C) CEREBRAL HEMORRHAGE
    1) WITH POISONING/EXPOSURE
    a) CASE REPORT: A 25-year-old man was stung on the right foot by a scorpion. He developed immediate severe local pain, followed 30 minutes later by severe headache, vomiting and then loss of consciousness. Immediately after the sting, his blood pressure was 160/110 mmHg. He was admitted to hospital comatose, blood pressure was 140/96 mmHg, pulse 80 beats/minute. CT scan revealed intracerebral hemorrhage (ICH) in the left caudate nucleus with intraventricular blood. Lumbar puncture revealed subarachnoid blood. EEG and carotid angiography were normal, and there was no laboratory evidence of coagulopathy. He recovered almost completely in 4 weeks with conservative treatment. The ICH was felt to be secondary to hypertension induced by the scorpion sting (Rai et al, 1990).
    D) SEIZURE
    1) WITH POISONING/EXPOSURE
    a) Seizures have been described after Mesobuthus tamulus sting (Bawaskar & Bawaskar, 2003; Bawaskar & Bawaskar, 1992).
    E) COMA
    1) WITH POISONING/EXPOSURE
    a) Encephalopathy, with manifestations ranging from confusion and agitation to coma, has been reported after Mesobuthus tamulus envenomation (Bawaskar & Bawaskar, 1992). In a series of 32 children with Mesobuthus tamulus envenomation, 4 (12.5%) developed encephalopathy (Das et al, 1995).

Gastrointestinal

    3.8.2) CLINICAL EFFECTS
    A) VOMITING
    1) WITH POISONING/EXPOSURE
    a) Vomiting is common in patients who develop systemic effects (Bawaskar & Bawaskar, 1992).
    B) EXCESSIVE SALIVATION
    1) WITH POISONING/EXPOSURE
    a) Excessive salivation is a fairly common cholinergic effect early in the course of patients who develop systemic envenomation (Bawaskar & Bawaskar, 1992).

Hepatic

    3.9.2) CLINICAL EFFECTS
    A) AMINOTRANSFERASE
    1) WITH POISONING/EXPOSURE
    a) Mild elevations in SGOT, SGPT and LDH have been reported after Mesobuthus tamulus envenomation (Santhanakrishnan et al, 1977).

Genitourinary

    3.10.2) CLINICAL EFFECTS
    A) PRIAPISM
    1) WITH POISONING/EXPOSURE
    a) Priapism is common with severe envenomation. In a series of 77 men with severe Mesobuthus tamulus stings, 68 (88%) developed priapism (Bawaskar & Bawaskar, 1996).
    B) ACUTE RENAL FAILURE SYNDROME
    1) WITH POISONING/EXPOSURE
    a) Acute renal failure may develop in patients with severe cardiovascular manifestations of envenomation. In a series of 24 patients with severe myocardial toxicity after Mesobuthus tamulus envenomation, 8 (33%) developed transient acute renal failure (Rajasekhar & Mohan, 2004).

Acid-Base

    3.11.2) CLINICAL EFFECTS
    A) METABOLIC ACIDOSIS
    1) WITH POISONING/EXPOSURE
    a) Mild metabolic acidosis was fairly common in a study of 8 patients admitted to an ICU with Mesobuthus tamulus envenomation. The mean serum HCO3 was 18.3 mmol/L with a range of 13.1 to 22.3 mmol/L (Karnad, 1998).

Dermatologic

    3.14.2) CLINICAL EFFECTS
    A) EXCESSIVE SWEATING
    1) WITH POISONING/EXPOSURE
    a) Excessive sweating is common in severe envenomation (Bawaskar & Bawaskar, 2000). It was reported in 25 out of 32 children (78%) with severe envenomation in one study (Das et al, 1995).
    B) PAIN
    1) WITH POISONING/EXPOSURE
    a) Pain at the site of the sting is common, and in some cases may be quite severe (Bawaskar & Bawaskar, 1992). In patients with severe pain, it may radiate to adjacent dermatomes. In one series, 18 out of 62 patients (29%) had pain as the only manifestation of envenomation; these patients never developed systemic effects (Bawaskar & Bawaskar, 1992).
    C) EDEMA
    1) WITH POISONING/EXPOSURE
    a) The sting site usually has an unremarkable appearance, although mild swelling, small punctate hemorrhages, localized sweating, and blackish discoloration have been reported at the site (Bawaskar & Bawaskar, 1992; Bajaj et al, 1984).

Endocrine

    3.16.2) CLINICAL EFFECTS
    A) HYPERGLYCEMIA
    1) WITH POISONING/EXPOSURE
    a) In a series of 32 children with Mesobuthus tamulus sting, 30 patients developed signs and symptoms of systemic venom effects, and all of these children developed mild hyperglycemia and a 2 to 3-fold elevation of serum free fatty acids (Das et al, 1995).

Laboratory Monitoring

Monitoring Parameters Levels

    4.1.1) SUMMARY
    A) Monitor vital signs frequently.
    B) Those with systemic signs of intoxication should have serial ECGs and continuous cardiac monitoring with pulse oximetry. In addition, monitor serum electrolytes, renal function, hepatic enzymes, and labs to assess myocardial injury.
    C) Patients with dyspnea, hypoxia or evidence of pulmonary edema should have a chest radiograph.
    D) There is no specific laboratory study for scorpion toxins that is clinically useful.
    E) Laboratory studies should be targeted towards patient symptoms, and patients with mild symptoms may not need any specific studies.
    4.1.2) SERUM/BLOOD
    A) Monitor serum electrolytes and renal function in patients with signs and symptoms of systemic venom effects. Severe dehydration has developed in patients with profuse sweating and repeated episodes of vomiting. Acute renal failure has developed in patients with severe cardiovascular manifestations.
    B) Monitor cardiac enzymes in patients with evidence of myocardial toxicity (ECG changes, hypotension, pulmonary edema, persistent tachycardia, or severe hypertension).
    C) Monitor serum aminotransferases and LDH in patients with systemic venom effects.
    4.1.3) URINE
    A) Monitor urine output in patients with hypotension, vasoconstriction or pulmonary edema.
    4.1.4) OTHER
    A) OTHER
    1) PULSE OXIMETRY
    a) Monitor pulse oximetry and/or arterial blood gases in patients with dyspnea, hypotension, or evidence of pulmonary edema.
    2) ECG
    a) Monitor serial ECGs and institute continuous cardiac monitoring in patients with systemic signs and symptoms.
    b) A variety of ECG changes have been described, including ST segment depression, tall T waves, ST elevation, fascicular block, QRS widening, and low voltage (Bawaskar & Bawaskar, 2000; Das et al, 1995; Bawaskar & Bawaskar, 1992; Bawaskar & Bawaskar, 1996; Santhanakrishnan et al, 1977).
    c) The ECG may suggest acute myocardial infarction (Bawaskar & Bawaskar, 1996).
    3) PULMONARY ARTERY CATHETER
    a) Insertion of a pulmonary artery catheter may be useful to guide treatment in patients with decreased perfusion, hypotension, or pulmonary edema.

Radiographic Studies

    A) CHEST RADIOGRAPH
    1) Obtain a chest radiograph in patients with dyspnea, hypoxia or evidence of pulmonary edema on physical exam.
    B) ECHOCARDIOGRAM
    1) Echocardiogram may be useful for evaluating patients with evidence of myocarditis (decreased perfusion, hypotension, pulmonary edema).
    2) Echocardiography may reveal transient left ventricular dysfunction, global hypokinesia and/or dilated cardiomyopathy. The mean ejection fraction in 24 patients with myocarditis after scorpion sting was 25.5% (SD 12.8%). Echocardiogram usually returns to normal with in several days to a few weeks (Rajasekhar & Mohan, 2004).

Treatment

Life Support

    A) Support respiratory and cardiovascular function.

Patient Disposition

    6.3.6) DISPOSITION/BITE-STING EXPOSURE
    6.3.6.1) ADMISSION CRITERIA/BITE-STING
    A) Any patients with worsening symptoms or systemic symptoms that are worrisome (eg, causing abnormal vital signs) should be admitted to the hospital, and may necessitate an ICU admission if they develop severe symptoms such as pulmonary edema requiring vasopressor and/or intubation. Patients should not be discharged until they are clearly improving and medically stable.
    6.3.6.2) HOME CRITERIA/BITE-STING
    A) Home care is not indicated in any patient following a potential envenomation.
    6.3.6.3) CONSULT CRITERIA/BITE-STING
    A) Depending on the severity of symptoms, an intensivist consultation may be needed for patients who develop pulmonary edema and require ICU care. A toxicologist or poison center may be involved at any time for advice and may help facilitate access to an antivenom.
    6.3.6.5) OBSERVATION CRITERIA/BITE-STING
    A) Patients with symptoms that are worsening or systemic symptoms should be sent to a healthcare facility for observation and observed for 4 to 6 hours or until they are clearly improving. Criteria for discharge include patients who are medically stable and clearly improving.

Monitoring

    A) Monitor vital signs frequently.
    B) Those with systemic signs of intoxication should have serial ECGs and continuous cardiac monitoring with pulse oximetry. In addition, monitor serum electrolytes, renal function, hepatic enzymes, and labs to assess myocardial injury.
    C) Patients with dyspnea, hypoxia or evidence of pulmonary edema should have a chest radiograph.
    D) There is no specific laboratory study for scorpion toxins that is clinically useful.
    E) Laboratory studies should be targeted towards patient symptoms, and patients with mild symptoms may not need any specific studies.

Range Of Toxicity

Summary

    A) A single sting can cause severe, even fatal envenomation. Children appear to develop more severe toxicity than adults.

Minimum Lethal Exposure

    A) A single sting can cause lethal envenomation. Fatality rates in reported case series of patients presenting to hospital after Mesobuthus tamulus sting have ranged from 2% to 30% (Bawaskar & Bawaskar, 1992). These high mortality rates are reported from settings where medical care is extremely limited.

Maximum Tolerated Exposure

    A) A single sting can cause severe, even fatal envenomation. Children appear to be more likely to develop severe toxicity than adults (Das et al, 1995).

Pharmacology Toxicology

Toxicologic Mechanism

    A) Scorpion venom activates sodium channels, causing increased neurotransmitter release (Bawaskar & Bawaskar, 2000). In severe cases, the result is initial mild cholinergic manifestations (ie, vomiting, sweating, priapism, hypersalivation) followed by sustained adrenergic excess secondary to catecholamine release (ie, hypertension, tachycardia, myocardial failure and pulmonary edema) (Bawaskar & Bawaskar, 1992).
    B) A number of toxins have been isolated from the Mesobuthus tamulus venom and include Iberiotoxin (a high conductance calcium activated potassium channel blocker) and PoTx (a high molecular weight polypeptide pulmonary edema producing toxin) which are both considered lethal. The mechanism of these toxins are different, which can result in various signs and symptoms of toxicity (Deshpande et al, 2008).

References

General Bibliography

    1) Aksel G, Guler S, Dogan NO, et al: A randomized trial comparing intravenous paracetamol, topical lidocaine, and ice application for treatment of pain associated with scorpion stings. Hum Exp Toxicol 2015; 34(6):662-667.
    2) American Heart Association: 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2005; 112(24 Suppl):IV 1-203. Available from URL: http://circ.ahajournals.org/content/vol112/24_suppl/. As accessed 12/14/2005.
    3) Bajaj S, Gupta OP, Saxena PC, et al: Scorpion sting induced myocarditis a report of five cases. Clinician 1984; 48:358-63.
    4) Bawaskar HS & Bawaskar PH : Efficacy and safety of scorpion antivenom plus prazosin compared with prazosin alone for venomous scorpion (Mesobuthus tamulus) sting: randomised open label clinical trial. BMJ 2011; 342:c7136-.
    5) Bawaskar HS & Bawaskar PH: Clinical profile of severe scorpion envenomation in children at rural setting. Indian Pediatrics 2003; 40:1072-1075.
    6) Bawaskar HS & Bawaskar PH: Management of cardiovascular manifestations of poisoning by the Indian red scorpion (Mesobuthus tamulus). Br Heart J 1992; 68:478-480.
    7) Bawaskar HS & Bawaskar PH: Prazosin therapy and scorpion envenomation. J Assoc Physicians India 2000; 48(12):1175-1180.
    8) Bawaskar HS & Bawaskar PH: Scorpion envenoming and the cardiovascular system. Trop Doct 1997; 27(1):6-9.
    9) Bawaskar HS & Bawaskar PH: Severe envenoming by the Indian red scorpion Mesobuthus tamulus: the use of prazosin therapy. Q J Med 1996; 89:701-704.
    10) Das S, Nalini P, Ananthakrishnan S, et al: Scorpion envenomation in children in southern India. J Trop Med Hygiene 1995; 98(5):306-308.
    11) Dehesa-Davila M, Alagon AC, & Possani LD: Clinical toxicology of scorpions stings In: Meier J & White J (Eds): Handbook of Clinical Toxicology of Animal Venoms and Poisons, CRC Press, Inc, Boca Raton, Florida, USA, 1995, pp 221-238.
    12) Deshpande SB , Pandey R , & Tiwari AK : Pathophysiological approach to the management of scorpion envenomation. Indian J Physiol Pharmacol 2008; 52(3):311-314.
    13) Friedman WF & George BL : Treatment of congestive heart failure by altering loading conditions of the heart. J Pediatr 1985; 106(5):697-706.
    14) Gadwalkar SR, Bushan S, Pramod K, et al: Bilateral cerebellar infarction: a rare complication of scorpion sting. J Assoc Physicians India 2006; 54:581-583.
    15) Gaitonde BB, Jadhav SS, & Bavarkar HS: Pulmonary edema after scorpion sting (letter). Lancet 1978; 1:445-446.
    16) Ilbawi MN, Idriss FS, DeLeon SY, et al: Hemodynamic effects of intravenous nitroglycerin in pediatric patients after heart surgery. Circulation 1985; 72(3 Pt 2):II101-II107.
    17) Jain MK, Indurkar M, Kastwar V, et al: Myocarditis and multiple cerebral and cerebellar infarction following scorpion sting. J Assoc Physicians India 2006; 54:491-492.
    18) Kankonkar RC, Kulkurni DG, & Hulikavi CB: Preparation of a potent anti-scorpion-venom-serum against the venom of red scorpion (Buthus tamulus). J Post Grad Med 1998; 44:85-92.
    19) Karnad DR: Haemodynamic patterns in patients with scorpion envenomation. Heart 1998; 79(5):485-489.
    20) Kleinman ME, Chameides L, Schexnayder SM, et al: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Part 14: pediatric advanced life support. Circulation 2010; 122(18 Suppl.3):S876-S908.
    21) Koch-Weser J: Hypertensive emergencies. N Engl J Med 1974; 290:211.
    22) Kumar PM, Krishnamurthy S, Srinivasaraghavan R, et al: Predictors of myocardial dysfunction in children with Indian red scorpion (Mesobuthus tamulus) sting envenomation. Indian Pediatr 2015; 52(4):297-301.
    23) Laitinen P, Happonen JM, Sairanen H, et al: Amrinone versus dopamine-nitroglycerin after reconstructive surgery for complete atrioventricular septal defect. J Cardiothorac Vasc Anesth 1997; 11(7):870-874.
    24) Lucas SM & Meier J: Biology and distribution of scorpions of medical importance In: Meier J & White J (Eds): Clinical toxicology of animal venoms and poisons, CRC Press, Inc, Boca Raton, FL, USA, 1995, pp 205-219.
    25) McMillian WD, Trombley BJ, Charash WE, et al: Phentolamine continuous infusion in a patient with pheochromocytoma. Am J Health Syst Pharm 2011; 68(2):130-134.
    26) Murthy KRK & Zare MA: Scorpion antivenom reverses metabolic, electrocardiographic, and hormonal disturbances caused by the Indian red scorpion Mesobuthus tamulus concanesis, Pocock envenomation. J Venom Anim Toxins 2002; 8(1):1-16.
    27) Nam YT, Shin T, & Yoshitake J: Induced hypotension for surgical repair of congenital dislocation of the hip in children. J Anesth 1989; 3(1):58-64.
    28) Narayanan P, Mahadevan S, & Serane VT: Nitroglycerine in scorpion sting with decompensated shock. Indian J Pediatr 2006; 43(7):613-617.
    29) Natu VS, Murthy RK, & Deodhar KP: Efficacy of species specific anti-scorpion venom serum (AScVS) against severe, serious scorpion stings (Mesobuthus tamulus concanesis Pocock)--an experience from rural hospital in western Maharashtra. J Assoc Physicians India 2006; 54:283-287.
    30) Pandi K , Krishnamurthy S , Srinivasaraghavan R , et al: Efficacy of scorpion antivenom plus prazosin versus prazosin alone for Mesobuthus tamulus scorpion sting envenomation in children: a randomised controlled trial. Arch Dis Child 2014; 99(6):575-580.
    31) Peberdy MA , Callaway CW , Neumar RW , et al: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care science. Part 9: post–cardiac arrest care. Circulation 2010; 122(18 Suppl 3):S768-S786.
    32) Product Information: NITROPRESS(R) injection for IV infusion, Sodium Nitroprusside injection for IV infusion. Hospira, Inc., Lake Forest, IL, 2007.
    33) Product Information: NITROPRESS(R) injection, sodium nitroprusside injection. Hospira,Inc, Lake Forest, IL, 2004.
    34) Product Information: Phentolamine Mesylate IM, IV injection Sandoz Standard, phentolamine mesylate IM, IV injection Sandoz Standard. Sandoz Canada (per manufacturer), Boucherville, QC, 2005.
    35) Product Information: dobutamine HCl 5% dextrose intravenous injection, dobutamine HCl 5% dextrose intravenous injection. Baxter Healthcare Corporation (per DailyMed), Deerfield, IL, 2012.
    36) Product Information: dopamine hcl, 5% dextrose IV injection, dopamine hcl, 5% dextrose IV injection. Hospira,Inc, Lake Forest, IL, 2004.
    37) Rai M, Shukla RC, & Varma DN: Intracerebral hemorrhage following scorpion bite. Neurology 1990; 40:1801.
    38) Raichur DV, Magar VS, Wari PK, et al: Hemiplegia and motor aphasia following scorpion sting. Indian J Pediatr 2001; 68(7):669-670.
    39) Rajasekhar D & Mohan A: Clinical and echocardiographic findings in patients with myocardial toxicity due to scorpion sting. Natl Med J India 2004; 17(6):307-309.
    40) Rasch DK & Lancaster L: Successful use of nitroglycerin to treat postoperative pulmonary hypertension. Crit Care Med 1987; 15(6):616-617.
    41) Rhoney D & Peacock WF: Intravenous therapy for hypertensive emergencies, part 1. Am J Health Syst Pharm 2009; 66(15):1343-1352.
    42) Rimsza ME, Zimmerman DR, & Bergeson PS: Scorpion envenomation. Pediatrics 1980; 66:298-301.
    43) Santhanakrishnan BR, Ranganathan G, & Ananthasubramanian P: Cardiovascular manifestations of scorpion sting in children. Ind Pediatr 1977; 14:353-356.
    44) Singh D, Akingbola O, Yosypiv I, et al: Emergency management of hypertension in children. Int J Nephrol 2012; 2012:420247.
    45) Sundararaman T, Olithselvan M, Sethuraman KR, et al: Scorpion envenomation as a risk factor for development of dilated cardiomyopathy. J Assoc Physicians India 1999; 47(11):1047-1050.
    46) U.S. Department of Health and Human Services; National Institutes of Health; and National Heart, Lung, and Blood Institute: The seventh report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. U.S. Department of Health and Human Services. Washington, DC. 2004. Available from URL: http://www.nhlbi.nih.gov/guidelines/hypertension/jnc7full.pdf. As accessed 2012-06-20.