scorpion sting

Scorpion sting

Scorpion stings can be very painful but rarely life-threatening. Although most scorpion stings cause only localized pain without life-threatening envenoming, about one third of stings cause systemic envenoming which can result in death. Young children, and sometimes the very old, are most at risk of serious complications. Scorpions are shy nocturnal predatory animals that usually spend the day under rocks, logs, but often live in houses in floors and in crevices, which explains the high incidence of scorpion stings involving children in many parts of the world. DO NOT stick your hands or feet in these hiding places.

The severity of scorpion stings is related to the presence of neurotoxins in the venom that cause a sudden release of neurotransmitters from the autonomic nervous system, predominantly sympathetic. There is also a strong inflammatory response that worsens symptoms, including those of a respiratory nature. Several vital functions may be directly affected, including the cardiovascular, respiratory, and neuromuscular systems. Hypertension is constant at the beginning of systemic envenoming and sometimes has a severe cardiac and respiratory impact.

In the United States, the bark scorpion, found mainly in the desert Southwest, is the only scorpion species with venom potent enough to cause severe symptoms. Worldwide, only about 30 of the estimated 1,500 species of scorpions produce venom toxic enough to be fatal. But with millions of scorpion stings occurring each year, often in areas with a lack of access to medical care, deaths due to scorpion stings are a significant public health problem in parts of Mexico, South America, North Africa, the Middle East and India.

Scorpion stings are common emergency events in many parts of the world 1). The estimated annual global incidence, based on national health data, is about 1.5 million envenomings involving 2600 deaths (Figure 2). Although the incidence of scorpion stings is higher in adults, the severity of envenoming is significantly greater in children, in whom the case fatality rate is up to ten times higher than in adults 2).

Healthy adults usually don’t need treatment for scorpion stings. But if a child is stung, the same amount of venom may have more-serious consequences, so seek immediate medical care.

Your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

Can you die from a scorpion sting?

Death from scorpion stings rarely occurs in people older than 6 years. If symptoms rapidly become worse within the first 2 to 4 hours after a scorpion sting, a poor outcome is more likely. Symptoms may last several days or longer. Some deaths have occurred as late as weeks after the scorpion sting if complications develop.

Figure 1. Striped bark scorpions

bark scorpion
bark scorpionbark scorpion

Composition of scorpion venom

The venomous apparatus of the scorpion consists of a venom vesicle comprising a pair of joined glands in the telson, the last segment of the post-abdomen 3). This venom vesicle is surrounded by a striated muscular layer facilitating and regulating the ejection of venom. This ability partly explains the variation in intensity of symptoms and the possibility of “dry” stings, i.e., without inoculation of venom.

Scorpion venom is composed of toxins and enzymes with neurological tropism acting on ion channels of excitable cells. Classification of toxins is based on four distinct criteria 4): the involved ion channel (in particular those for sodium, potassium, chlorine and calcium); the specific receptor to which the toxin binds within the ion channel; the three-dimensional structure of the toxin; and the type of response induced (activation/inactivation of the receptor). The venom of the same scorpion can have multiple toxins that may interact with each other, modulating the response of the ion channels involved and leading to complex and rapidly progressive symptoms 5).

Toxins binding to the sodium channel are most important, at least with regard to mammals, particularly humans 6). Among the categories currently described, two main types can be distinguished, that is toxins-α and toxins-β. Toxins-α (known as “potential-dependent”) present in the venom of paleotropical scorpions have a binding affinity for their receptor proportional to the intensity of the polarization of the membrane. Toxins-α inactivate the closing potential of the sodium channel, without modifying the opening potential, so act only when the channel is opened. The main consequence is strong depolarization of the membrane, followed by a drop in excitability 7). At high doses, they prolong the action potential of excitable cells and induce paralysis and cardiac arrhythmia 8). Toxins-β, isolated from the venom of American scorpions, act on another site of the sodium channel activated at a lower action potential and independently of the membrane potential 9), resulting in myoclonic or spastic muscular responses. However, some South American scorpions, such as Tityus serrulatus, have a toxin (also called γ-toxin) which has a combined effect, i.e., it blocks the opening of the channel but also blocks its closure when the channel is already open 10).

Other toxins affecting membrane ion channels, including those for potassium 11), are of great interest in neurobiology and pharmacology, but seem to have a subsidiary role in human envenoming. However, all these toxins can have a synergistic action on clinical symptoms, resulting in paradoxical syndromes or severe complications. Consequently, a toxin which may have individually mild clinical effects can become toxic, or increase the toxicity of other toxins, when they are associated.

Very often, studies pit cardiovascular complications against respiratory failure while they both could be the consequence of a) a difference in the composition of the venom, b) a delayed consultation, or even c) an inappropriate initial treatment.

What to do for a scorpion sting

Most stings from North American scorpions do not need treatment. Children 6 years and younger are more likely to have harmful effects from poisonous types of scorpions.

The recommended treatment is to wash the scorpion sting site with soap and water, apply antiseptic and a cold pack to the sting area and, if you need to, take a mild pain-relief medicine, such as acetaminophen. If you are not up to date with your tetanus shot, you should go to the doctor for immunization.

  • Clean the area thoroughly with soap and water.
  • Place ice (wrapped in a clean cloth) on the site of the sting for 10 minutes and then off for 10 minutes. Repeat this process. If the person has problems with blood circulation, decrease the time that the ice is on the area to prevent possible skin damage.
  • Keep the affected area still, if possible, to prevent the venom from spreading.
  • Loosen clothing and remove rings and other tight jewelry.
  • Give the person diphenhydramine (Benadryl and other brands) by mouth if they can swallow. This antihistamine drug may be used alone for mild symptoms.

Scorpion sting complications

The very old and the very young are most likely to die of untreated venomous scorpion stings. The cause is usually heart or respiratory failure occurring some hours after the sting. Very few deaths from scorpion stings have been reported in the United States.

Another possible complication of scorpion stings, though rare, is a severe allergic reaction (anaphylaxis).

Figure 2. Scorpion stings worldwide incidence and deaths

Scorpion stings worldwide incidence and deaths

Note: enven = envenomings; M = million

[Source 12)]

Scorpion sting causes

Scorpions are arthropods — a relative of insects, spiders and crustaceans. The average scorpion is about 3 inches (7.6 centimeters) long. Scorpions have eight legs and a pair of lobster-like pinchers and a tail that curves up. They sting rather than bite, using the stinger in their tails. The venom itself contains a complex mix of toxins that affect the nervous system (neurotoxins).

Scorpions are nocturnal creatures that resist stinging unless provoked or attacked. They can control the amount of venom they release — depending on how threatened they feel — so some stings may be almost entirely venomless.

Risk factors for scorpion sting

Certain factors can increase your risk of a scorpion sting:

  • Geography. In the United States, scorpions mainly live in the desert Southwest, primarily Arizona, New Mexico and parts of California. Worldwide, they’re
  • found most often in Mexico, North Africa, South America, the Middle East, and India.
  • Environment. Bark scorpions live under rocks, logs and tree bark — hence, the name. You’re especially likely to encounter one when you’re hiking or camping. Bark scorpions are also the most common house scorpion, hiding in firewood, garbage pails, bed linen and shoes.
  • Travel. Not only are you more likely to encounter more-dangerous scorpions while traveling in certain parts of the world, you might bring them home with you. Scorpions can hide in clothing, luggage and shipping containers.

Scorpion sting prevention

Scorpions tend to avoid contact. If you live in an area where scorpions are common, prevent chance meetings by doing the following:

  • Remove piles of rocks or lumber from around your house and don’t store firewood against the house or inside.
  • Keep grass closely mowed, and prune bushes and overhanging tree branches, which can provide a path to your roof for scorpions.
  • Caulk cracks, install weather stripping around doors and windows, and repair torn screens.
  • Inspect and shake out gardening gloves, boots and clothing that haven’t been used for a while. Always wear shoes.
  • When hiking or camping, wear long sleeves and pants and check your sleeping bag for scorpions before you crawl in.
  • When traveling in areas where lethal scorpions are common — especially if you’re camping or staying in rustic accommodations — shake out your clothing, bedding and packages often. Sleep under a mosquito net. If you have a known allergy to insect stings, carry an epinephrine injector, such as EpiPen.

If you do find a scorpion near your home or campsite, use tongs to gently remove the scorpion away from people.

Scorpion sting symptoms

The first symptom of scorpion envenoming is localized pain, which reflects the penetration of the venom and is a valuable warning signal, especially in children. Pain is present in more than 95% of cases of envenoming and may be associated with edema (swelling) and erythema (redness) (in 20% of cases), more rarely small blisters. Sometimes these symptoms may be quite intense, even if you don’t see redness or swelling.

The systemic manifestations of scorpion envenoming occur in less than a third of victims of scorpion stings. These manifestations result from the release of neurotransmitters in response to the actions of the toxin on sodium channels. Symptoms develop rapidly, within a few hours, leading to a range of clinical pictures according to the species of scorpion.

Overstimulation of the sympathetic system increases blood levels of catecholamines, resulting in a characteristic “adrenergic (autonomic) storm” which consists of cardiac (tachycardia, peripheral vasoconstriction, hypertension, diaphoresis), metabolic (hyperthermia, hyperglycemia), urogenital (bladder dilatation, urinary retention, ejaculation in males), respiratory (bronchial dilation, tachypnea), and neuromuscular (mydriasis, tremor, agitation, convulsions) complications.

In contrast, a cholinergic (or muscarinic) syndrome can occur involving the parasympathetic nervous system. This combines a hypersecretion syndrome (salivation, sweating, vomiting, urinary incontinence, bronchial hypersecretion, and diarrhea), abdominal pain, miosis, bronchospasm, bradycardia with hypotension and, in the male, priapism. This syndrome seems to be rarer, delayed, or masked by the adrenergic storm.

In addition, the release of inflammatory substances or vasodilators (kinins, prostaglandins) reinforces and exacerbates some symptoms (fever, dyspnea, visceral infarction) which can become dominant. Therefore, each vital organ can be affected and endangered by envenoming, treatment of which becomes a priority.

The early and persistent cardiac effects observed in scorpion envenoming are caused by release of catecholamines. The first symptoms, ie, tachycardia, arrhythmia, and hypertension, rapidly impair cardiac function. Peripheral vasoconstriction, probably reinforced by the action of kinins, accentuates cardiac ischemia, as evidenced by changes on electrocardiography (in particular QT prolongation, increased or inverted T waves, and ST-segment abnormalities), and echocardiography and scintigraphy confirm decreased myocardial perfusion. These changes can lead to myocardial necrosis inducing heart failure and death. More generally, the systolic ejection fraction is significantly lowered, explaining the respiratory effects of acute pulmonary edema, acute heart failure, and cardiogenic shock. This evolution is the consequence of a succession of events related to the adrenergic storm and exacerbation of the inflammatory response, as suggested by high plasma concentrations of kinins, prostaglandins, and inflammatory cytokines, including interleukins 1 and 6, interferon gamma, and tumor necrosis factor alpha.

Similar mechanisms (vascular constriction, increased peripheral vascular resistance, local edema) may explain some visceral impairments, including those affecting the kidney, mesentery and brain. Finally, blood electrolyte disturbances are reflected clinically by cardiac, renal, and metabolic disorders. Various electrolytic disturbances due to catecholamine release (hyperkalemia, hyponatremia, hypocalcemia), hyperglycemia, acidosis, or even myocardial necrosis may accentuate these complications.

The neuromuscular hyperexcitability entails abnormal movements, twitching, tremors, convulsions, and cramps affecting all the skeletal muscles, but predominantly the cranial nerves. Rapid aberrant eye movements are likely to be more frequent during envenoming by Centruroides, found in North and Central America. Movements are bilateral and symmetrical, horizontal or rotary, suggesting a peripheral origin, which some authors have attributed to cerebral edema, potentially due to vasoconstriction of brain capillaries, including those in the thalamus. The convulsive forms sometimes attributed to hyperthermia and dehydration in very young children could be of the same origin. An adrenergic etiology remains the most probable, perhaps accentuated by individual susceptibility or age.

Signs and symptoms at the site of scorpion sting may include:

  • Pain, which can be intense for several hours
  • Numbness and tingling in the area around the sting
  • Slight swelling in the area around the sting

Signs and symptoms related to widespread (systemic) venom effects usually occur in children who are stung and may include:

  • Difficulty breathing
  • Muscle twitching or thrashing
  • Unusual head, neck and eye movements
  • Drooling
  • Double vision
  • Sweating
  • Abdominal cramps
  • Inability to hold in stool
  • Nausea and vomiting
  • Itching of the nose and throat
  • Spasm of the larynx (voice box)
  • Tongue that feels thick
  • High blood pressure (hypertension)
  • Accelerated heart rate (tachycardia) or irregular heart beat (arrhythmia)
  • Restlessness or excitability or inconsolable crying (in children)
  • Restlessness
  • Seizures
  • Stiffness
  • Anxiety
  • Convulsions
  • Paralysis

As with other stinging insects, such as bees and wasps, it is possible for people who have previously been stung by scorpions to also have allergic reactions with subsequent stings. These subsequent stings are sometimes severe enough to cause a life-threatening condition called anaphylaxis. Signs and symptoms in these cases are similar to those of anaphylaxis caused by bee stings and can include hives, trouble breathing, and nausea and vomiting.

  • Get immediate medical care for a child stung by a scorpion.

Scorpion sting diagnosis

Your history and symptoms are usually all your doctor needs to make a diagnosis. If you have severe symptoms, you may have blood or imaging tests to check for the effects of the venom on your liver, heart, lungs and other organs.

Scorpion sting treatment

Most scorpion stings don’t need medical treatment. But if symptoms are severe, you may need to receive care in a hospital. You may be given sedatives for muscle spasms and drugs through a vein (intravenously) to treat high blood pressure, agitation and pain.

Use of analgesics, even if they are not the most essential drugs in envenoming, is still important because pain is frequent and intense. It can be useful to administer analgesics with an anti-inflammatory action, such as salicylates, mindful that use of salicylates could trigger Lyell’s syndrome or Reye’s syndrome, the latter occurring mostly in children during viral infections treated by salicylates 13). The incidence of Reye’s syndrome, the symptoms of which can be confused with worsening of envenoming, is low at about 0.8 cases per million children 14), but is often fatal. Therefore, it is necessary to assess the risk/benefit ratio, taking into account that 15%–20% of scorpion stings can show severe progression and 0.5%–1% of these stings can be fatal in children, and consider other treatments that could also be beneficial. Some authors recommend local anesthesia with 1% lignocaine 15). In contrast, morphine or its derivatives or analogs (codeine, tramadol), although very effective 16), should be avoided because the opioid receptor agonists inhibit noradrenaline reuptake, which may potentiate their effects; these agents also cause respiratory depression, worsening the patient’s respiratory condition.

Anti-inflammatory drugs have never been subjected to formal clinical studies on the treatment of scorpion envenoming. However, there is no doubt that their therapeutic value is significant, even taking into account the risk of side effects. Experimental studies have shown that many biological markers of inflammation are involved in scorpion envenoming, and have been confirmed in the clinic. So there are new issues for clinical research. It is indeed easy to treat pain with analgesics having an anti-inflammatory effect, such as salicylates.

Many drugs aiming at cardiac treatment have been proposed to treat the hypertension, arrhythmia, heart failure, and pulmonary edema associated with scorpion envenoming. However, it should be borne in mind that the main origin of these symptoms is the increase in vascular resistance caused by peripheral vasoconstriction as a result of the action of catecholamines.

Among the vasodilators, the α1-adrenergic blockers, in particular prazosin, are of interest. Prazosin is recommended for the treatment of scorpion envenoming, especially in India 17). This drug is easy to use and has no major contraindications. Prazosin is more effective than nifepidine which blocks calcium ion influx of smooth muscle cells in the arterioles and inhibits their contraction 18). Hydralazine inhibits release of calcium ions in the smooth muscle of the vascular wall. Although effective, hydralazine has several disadvantages, including sympathetic stimulation which increases heart rate, with a risk of myocardial infarction, and an increase in plasma renin, leading to urinary retention requiring treatment with a β2-adrenergic blocker and diuretic. Further, hydralazine administered parenterally produces a prolonged hypotensive response which is difficult to control. 18 Captopril, a drug that inhibits the conversion of angiotensin has also been suggested 19). However, captopril inhibits degradation of bradykinin, which plays an important role in the development of acute pulmonary edema 20). Clonidine is an agonist of α2-adrenergic receptors that inhibits sympathetic activity. It causes a decrease in heart rate and peripheral blood pressure. Clonidine could be a useful drug, but to the author’s knowledge, has never been evaluated in the treatment of scorpion envenoming.

When heart failure is confirmed, many practitioners use dobutamine alone or in combination with diuretics or antiarrhythmics. Gupta et al 21) showed that prazosin is slightly better than dobutamine in terms of faster recovery, and also because it is easier to administer. However, this could be due to the particular circumstances or scorpion species involved, given that heart failure is a late complication of scorpion envenoming.

Neuromuscular disorders are most often treated with drugs activating gamma butyric acid (GABA) receptors that inhibit the excitability of postsynaptic neurons. Benzodiazepines have the advantage over other anticonvulsants, such as barbiturates (eg, phenobarbitone) because of their rapid distribution in the organism and short half-life. Barbiturates also have a depressive effect on respiration. Midazolam is the most widely used, particularly in North America 22). Elsewhere, particularly in Africa and the Middle East, diazepam is used extensively 23). In addition, benzodiazepines are beneficial in the treatment of hypertension and could be the initial drug of choice in the treatment of scorpion envenoming.

In general, antiparasympathetic drugs, such as atropine, are not recommended routinely in the treatment of scorpion envenoming. These cause blockage of sweating, which is essential for temperature regulation, especially in children, and potentiate the adrenergic effects of scorpion venom, increasing hypertension and ischemic complications 24). However, these drugs can be useful in cases of severe bradycardia or complete atrioventricular block, which are sometimes observed.

The choice between the various available drugs is difficult because the indications and dosages differ depending on: venom composition, which varies according to species and even individuals; the amount of venom injected; complications related to progression of envenoming, including delay in consultation; side effects of the drug; and modalities of drug administration, especially in peripheral health centers where there is often no doctor present.

Passive immunotherapy

The use of scorpion antivenom remains controversial because of concerns about effectiveness, side effects (more of a concern with older, less purified formulations), cost and access to care. Antivenom is most effective if given before symptoms develop, so children seen in remote rural emergency rooms, where access to medical centers and intensive care units is limited, are often treated with antivenom as a precaution. Also, if you have more-severe symptoms, your doctor may recommend the antivenom.

Antivenoms are particularly controversial in Africa and India with regard to their efficacy and usefulness in the treatment of scorpion envenoming for several reasons 25). First, there is a fear of side effects which dates back to the time when poorly refined whole IgG were used. The case fatality rate attributable to scorpion stings, albeit relatively low even at that time (1%–2%), was offset by the high incidence of side effects (occurring in at least 50% of patients treated with antivenom), some of which are life-threatening. This is no longer the situation with the advent of F(ab’)2, the side effects of which are rare (<5%) and generally mild 26). Second, there has been concern about incorrect administration of antivenom, either by an inappropriate route (other than intravenous) or at insufficient doses. Indeed, most treatments, including those used in clinical trials, used antivenoms with a neutralizing titer of about 10 ED50 (i.e., 1 mL of antivenom neutralized an amount of venom corresponding to 10 LD50), while the current antivenoms show a neutralizing titer of more than 50 ED50 (Table 2), are 3–5 times more effective. Finally, clinical trials performed in order to confirm the efficacy of antivenoms have been very few in number and often biased.55 However, a randomized placebo-controlled, blinded clinical trial carried out by Boyer et al46 showed that: antivenom removed the venom from the plasma compartment in less than one hour (versus more than 4 hours on average for the placebo group); the benzodiazepine dose needed was significantly lower in the group treated by antivenom; and cure was achieved in less than 4 hours in all patients treated with antivenom (versus only 15% in the control group).

Your treatment will also depend on whether your doctor determines that your signs and symptoms are due to an allergic reaction rather than the effects of the venom.

The severity of scorpion envenoming may be evaluated by a scoring system. Several scales have been proposed, and an attempt at consensus was recently published 27). Three grades are generally used, that is grade I for local events, grade II for mild systemic symptoms, and grade III for life-threatening envenoming. The first group represents about 70% of patients, the second 20%, and the third less than 10%.

Immunotherapy, provided that the antivenom is appropriate, of high-quality, and accessible, is both curative because it eliminates the venom and preventive because it reduces the risk of subsequent complications. For these reasons, it is essential to administer antivenom as soon as possible after the sting. Moreover, this should be made known to the public and implies organizational logistics (distribution and stock management in peripheral health centers, health staff training). The main limitation to the use of antivenoms is their accessibility, either because of supply problems or cost, which is sometimes quite high. Table 2 provides a non-exhaustive list of currently marketed antivenoms.

Symptomatic treatment is needed in the event of progression of symptoms and complications of envenoming that may appear before administration of antivenom, which is frequently due to delayed consultation. The two approaches are complementary. However, combination of both is highly dependent on local conditions, health center resources, and the level of training of health personnel. For example, use of some drugs is not desirable in remote health centers, which often lack doctors, while others can be easily administered. Finally, we need to take into account the severity of envenoming, which is greatly influenced by delay in consultation. Fortunately, assessment of severity using a scoring system can largely resolve this problem, enabling treatment to fit the grade of envenoming (Table 1).

Symptomatic treatment only is recommended in grade I (local) envenoming, for which immunotherapy is not helpful and too expensive. Salicylates are recommended at this stage (aspirin 10 mg/kg orally every 4 hours for children and adults), even if they are not in use in some countries, like the United States. Systemic envenoming (grade II and III) requires immunotherapy in addition to administration of salicylates. The antivenom dosage depends on its neutralizing titer. Administration should be done via the intravenous route, either as a direct slow intravenous push in cases of severe envenoming (grade III) or by infusion in 250 mL of saline administered over 30 minutes. Immunotherapy might be repeated after two hours if cure is not obtained on the first attempt.

In cases of cardiac arrhythmia or hypertension, prazosin (30 μg/kg orally every 6 hours for 48 hours or until clinical improvement) can be used, and in combination with immunotherapy, including in remote health centers. If cardiovascular complications are significant (acute pulmonary edema, heart failure, shock), it is necessary to use more specialized treatment, especially given that specific investigations will be needed (eg, electrocardiography, echocardiography). Dobutamine should be considered (infusion of 10 μg/kg/minute until normalization of left ventricular ejection fraction, then 5 μg/kg every 12 hours). Neuromuscular disorders (tremors, cramps, convulsions) may be treated with benzodiazepines, based on clinical signs and response to treatment, ie, midazolam (0.05–0.2 mg/kg orally or intravenously) or diazepam (0.5 mg/kg intravenously or rectally) every 12 hours.

Table 1. Clinical score of scorpion envenoming and corresponding treatment

GradeSymptomsTreatment*
ILocal pain (sometime associated with local paresthesia, erythema, ecchymosis, blisters)Aspirin 10 mg/kg orally every 4 hours
IIMild systemic envenoming: Idem grade I + hyperthermia + Cardiovascular and respiratory symptoms: tachycardia, arrhythmia, dyspnea, hypertension/hypotension, electrocardiographic abnormalities, priapism Hypersecretory syndrome (salivation, sweating, bronchorrhea, nausea, vomiting, diarrhea, urination)
Digestive tract: abdominal distension, abdominal cramps
Neuromuscular disorders: dysfunction of either skeletal or cranial muscles: confusion, agitation, fasciculation, dystonia, vision disorders, ptosis, aberrant eye movements
Biological disorders: hyperleucocytosis, hyperglycemia, acidosis
Idem +

  1. Immunotherapy: dose depending on antivenom titer
  2. Prazosin 30 μg/kg orally every 6 hours
  3. Midazolam 0.05–0.2 mg/kg orally or IV (or diazepam 0.5 mg/kg IV or rectally) every 12 hours
IIILife-threatening envenoming: idem grade II + multivisceral failure
Cardiovascular symptoms: heart failure, cardiogenic shock, pulmonary edema
Diaphoresis
Neuromuscular disorders: dysfunction of both skeletal and cranial muscles: convulsions, paralysis, Glasgow score ≤6 (in absence of sedation)
Biological disorders: SaO2 < 90%, increasing biomarkers of cellular necrosis, electrolytic anomalies (decrease of Na+ and Ca++, increase of K+)
Idem +
Transfer to ICU

Note:

*See indications, precautions, and comments in the text.

Abbreviations: ECG, electrocardiogram; ICU, intensive care unit; IV, intravenously.

[Source 28)]

Table 2. List of the main marketed scorpion antivenoms

Name/ManufacturerFormulation and titerNeutralized species
Polyvalent scorpion antivenomNational Antivenom and Vaccine Production Center, Saudi ArabiaHorse purified F(ab’)2
Vial 1 mL (liquid)
Unspecified titer
Leiurus quinquestriatus
Androctonus crassicauda
Sérum antiscorpioniqueInstitut Pasteur de Tunis, TunisiaHorse purified F(ab’)2
Unspecified formulation and titer
Androctonus australis
Buthus occitanus
Sérum antiscorpioniqueInstitut Pasteur d’Algérie, AlgeriaHorse purified F(ab’)2
Vial 10 mL (liquid)
Unspecified titer
Androctonus australis
Scorpifav®Sanofi Pasteur, FranceHorse purified F(ab’)2
Vial 1 mL (liquid)
Neutralize 50 DL50/mL
Leiurus quinquestriatus
Androctonus australis Buthus occitanus
Soro antiescorpiônicoInstituto Butantan–BrasilHorse purified F(ab’)2
Vial 5 mL (liquid)
Neutralize 7.5 minimal lethal doses
Tityus serrulatus
Soro antiescorpiônicoInstituto Vital Brazil, BrasilHorse purified F(ab’)2
Unspecified formulation and titer
Tityus serrulatus
Suero antiescorpiónicoCentro de Biotecnología, VenezuelaHorse purified F(ab’)2 Vial 5 mL (liquid)
Neutralize 0.2 mg/mL
Tityus discrepans
Antiveneno escorpiónANLIS Dr Carlos Malbrán, ArgentinaHorse purified F(ab’)2
Vial 2 mL (liquid)
Neutralize 200 LD50/mL
Tityus trivittatus
Alacramyn® (Mexico), Anascorp® (US)Instituto Bioclon, MexicoHorse purified F(ab’)2
Vial 5 mL (lyophilized)
Neutralize 30 LD50/mL
Centruroides limpidus
Centruroides noxius
Centruroides suffusus
Centruroides meisei
Faboterápico, polivalente alacránBirmex, MexicoHorse purified F(ab’)2
Vial 5 mL (liquid)
Unspecified titer
Centruroides limpidus
Centruroides noxius
Centruroides suffusus
SAVP scorpion antivenomSouth African Vaccine Producers, South AfricaHorse purified F(ab’)2
Vial 5 mL (liquid)
Unspecified titer
Parabuthus transvaalicus
Polyvalent scorpion serumRazi Serum and Vaccine Research Institute, IranUnspecifiedUnspecified
Purified polyvalent antiscorpion serumVacsera, EgyptHorse purified F(ab’)2
Vial 1 mL (lyophilized)
Unspecified titer
Unspecified
Antiscorpion venom serumHaffkine Biopharmaceutical Corporation, IndiaHorse purified F(ab’)2
Vial 10 mL (lyophilized)
Neutralize 25 LD50/mL
Mesobuthus tamulus
Androctonus crassicauda antivenomRefik Saydam Hygiene Center, TurkeyHorse purified F(ab’)2, vial 10 mL (lyophilized),
neutralizes 500 LD50/mL
Androctonus crassicauda
[Source 29)]

Summary of treatment

Whatever the treatment, ie, antivenom or intensive care, it has been shown that mortality decreases wherever the management of scorpion stings has been anticipated and organized by health authorities 30). However, the choice between the two options requires realistic consideration of all relevant parameters, including logistics. In addition, mortality should not be the only endpoint; one should also consider the simplicity of management and rapidity of recovery. The complexity of contradictory clinical symptoms causes difficulty to choose symptomatic treatments, especially given that progression of symptoms and onset of complications may be rapid. While some drugs can be routinely used with a relevant and accurate protocol, many others remain the prerogative of the specialist. In contrast, treatment with antivenom, designed to eliminate venom from the organism rapidly, is likely to be the most logical and now easier to manage with low risks. Fragments of purified IgG are very effective and safe, even when administered by nonmedical personnel, provided that they have been trained. Administered early, they can prevent serious complications and reduce transfers to referral hospitals, but this strategy requires ready access to antivenom in remote health facilities.

In many cases, the combination of immunotherapy and symptomatic treatment remains a necessity. These treatment strategies potentiate each other, and give a satisfactory response to most common situations encountered in tropical countries 31). The training of health personnel regarding these combined treatment protocols should be extended to all countries where the incidence of scorpion stings is high. Public information on these new therapeutic strategies is essential in order to promote early presentation to health centers.

Scorpion sting home remedy

If a scorpion stings you or your child, follow the suggestions below. Healthy adults may not need further treatment, and these tips can help keep children safe until they see a doctor:

  • Clean the wound with mild soap and water.
  • Apply a cool compress to the affected area for 10 minutes. Remove it for 10 minutes, then reapply it. This helps reduce pain and slow the venom’s spread.
  • This is most effective in the first two hours after a sting occurs.
  • Don’t consume food or liquids if you’re having difficulty swallowing.
  • Take an over-the-counter pain reliever as needed. You might try ibuprofen (Motrin IB, Children’s Motrin, others) to help ease discomfort.

Check your or your child’s immunization records to be sure a tetanus vaccine is up to date.

References   [ + ]

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