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Androctonus bicolor
General Details, Taxonomy and Biology, Venom, Clinical Effects, Treatment, First Aid , Antivenoms
Androctonus bicolor "aeneas morph" male (Libya)  [ Original photo copyright © Eric Ythier ]
Family: Buthidae
Genus: Androctonus
Species: bicolor
Middle East + North Africa
Algeria, Egypt, Israel, Lebanon, Libya, Tunisia
Taxonomy and Biology
Adult Length ( mm ): 50 mm
Carapace and tergites are usually dark reddish brown or dark brown to black. Metasomal segments and telson vesicle is dark brown with black keels. Aculeus is dark brown. Pedipalps are blackish brown. Sternites are dark reddish brown. Legs are blackish brown.
Species Map
Small (Approx 20k) version
General: Venom Neurotoxins
Excitatory neurotoxins
General: Venom Myotoxins
Does not occur, based on current clinical evidence
General: Venom Procoagulants
Not present
General: Venom Anticoagulants
Not present
General: Venom Haemorrhagins
Not present
General: Venom Nephrotoxins
Not present
General: Venom Cardiotoxins
Possibly present
General: Venom Necrotoxins
Not present
General: Venom Other
Clinical Effects
General: Dangerousness
Severe envenoming possible, potentially lethal
General: Rate of Envenoming: 10-20%
General: Untreated Lethality Rate: 1-10%
General: Local Effects
Local severe pain only in most cases; local redness or sweating possible
General: Local Necrosis
Does not occur, based on current clinical evidence
General: General Systemic Effects
Variable non-specific effects which may include headache, nausea, vomiting, abdominal pain, diarrhoea, tachypnoea, respiratory distress, hypotension, dizziness, collapse or convulsions
General: Myotoxicity
Does not occur, based on current clinical evidence
General: Coagulopathy & Haemorrhages
Does not occur, based on current clinical evidence, except as a rare secondary effect
General: Renal Damage
Unlikely to occur
General: Cardiotoxicity
Cardiotoxicity may be direct or indirect, but is a feature of severe envenoming, with cardiac arrhythmias, cardiac failure.
General: Other
Hypovolaemic hypotension possible in severe cases due to fluid loss through vomiting and sweating.
First Aid
Description: First aid for scorpion stings (in areas where potentially dangerous species may be found)
1. After ensuring the patient and onlookers are not at risk of further scorpion stings, the victim should be reassured and persuaded to lie down and remain still. Some may be terrified, fearing sudden death and, in this mood, they may behave irrationally or even hysterically, a situation made worse by the intense pain often suffered. The basis for reassurance is the fact that most scorpion stings prove non-lethal and the effectiveness of modern medical treatment.
2. The sting wound should not be tampered with in any way. Wiping it once with a damp cloth to remove surface venom is unlikely to do much harm (or good) but the wound must not be massaged.
3. Though unproven, there is anecdotal evidence suggesting the application of a cold pack to the sting area may reduce pain. At least in Mexico, there is also anecdotal evidence suggesting local suction may be beneficial.
3. All rings or other jewellery on the bitten limb, especially on fingers, should be removed, as they may act as tourniquets if swelling develops.
4. The bitten limb should be immobilised as effectively as possible using an extemporised splint or sling; if available, crepe bandaging of the splinted limb is an effective form of immobilisation.
5. If there is any impairment of vital functions, such as problems with respiration, airway, circulation, heart function, these must be supported as a priority. In particular, for bites causing flaccid paralysis, including respiratory paralysis, both airway and respiration may be impaired, requiring urgent and prolonged treatment, which may include the mouth to mask (mouth to mouth) technique of expired air transfer. Seek urgent medical attention.
6. Do not use Tourniquets, cut, suck or scarify the wound or apply chemicals or electric shock.
7. Avoid peroral intake, absolutely no alcohol. No sedatives outside hospital. If there will be considerable delay before reaching medical aid, measured in several hours to days, then give clear fluids by mouth to prevent dehydration.
8. If the offending scorpion has been killed it should be brought with the patient for identification.
9. The scorpion sting victim should be transported as quickly and as passively as possible to the nearest place where they can be seen by a medically-trained person (health station, dispensary, clinic or hospital). The bitten limb must not be exercised as muscular contraction will promote systemic absorption of venom. If no motor vehicle or boat is available, the patient can be carried on a stretcher or hurdle, on the pillion or crossbar of a bicycle or on someone's back.
10. Most traditional, and many of the more recently fashionable, first aid measures are useless and potentially dangerous. These include local cauterization, incision, excision, amputation, injection or instillation of compounds such as potassium permanganate, phenol (carbolic soap) and trypsin, application of electric shocks or ice (cryotherapy), use of traditional herbal, folk and other remedies including the ingestion of emetic plant products and parts of the snake, multiple incisions, tattooing and so on. The role of suction by mouth, vacuum pump or syringe, combined incision and suction ("venom-ex" apparatus) is uncertain.

Treatment Summary
Most stings cause only severe local pain which can be treated using local anaesthetic infiltration. Systemic envenoming can develop rapidly, though occasionally may be delayed in onset, so caution in assessment is required. Young children are at greatest risk. Treatment of systemic envenoming is highly controversial.
Some general guidelines are clear for managing moderate to severe scorpion envenoming. Hypovolaemia secondary to venom induced vomiting and sweating is a significant risk; it is therefore important to manage fluid loss, if necessary with IV fluid replacement in the early stages. However, pulmonary oedema can occur in severe envenoming, especially in children, and while the cause may be other than fluid overload, careful attention to fluid balance is warranted. Vomiting should be controlled with appropriate pharmacotherapy; chlorpromazine or promethazine have been recommended in the past, but newer antiemetics might also be considered. For cardiaovascular dysfunction, potentially lethal, intervention with supportive pharmacotherapy has been suggested. Though not specifically tried for North African and Middle East scorpion envenoming, prazosin has been strongly advocated in this setting, with positive clinical experience in India. Atropine, though suggested by some to control some autonomic effects of envenoming, is considered contraindicated by others. Early support of respiration is appropriate, if impairment is evident, including consideration of intubation and ventilation. Regrettably, facilities for such treatment will not be available in many areas at risk of major scorpion envenoming.

Where antivenom is available, it should be considered in cases with severe, possibly moderate envenoming. It should only be given IV, as soon as possible once indicated, in a substantial dose. Precise dosing will vary between antivenom products, but it should be noted that the minimum or initial doses stated by some producers are too low and that recommendations to use the IM route or undertake skin sensitivity testing should be ignored. As with all antivenom therapy, both early and late adverse reactions are possible and must be considered and prepared for; specifically ensure that adrenaline (epinephrine) and resuscitation equipment is ready prior to commencing antivenom administration. Where possible, dilute antivenom up to 1:10 in sterile normal saline or similar and give as an IV infusion, starting slowly, looking for adverse reactions, then increasing the rate if no adverse reactions occur, aiming to give the entire dose over a short period (15-20 mins). Early achievement of high circulating levels of antivenom is crucial for effectiveness. All patients given antivenom should be advised of the possibility of and symptoms/signs of serum sickness, prior to discharge, and advised to return if serum sickness develops.
Key Diagnostic Features
Severe local pain, increased salivation, sweating, irritability, vomiting, cadrdirespiratory effects.
General Approach to Management
All cases should be treated as urgent & potentially lethal. Rapid assessment & commencement of treatment including appropriate antivenom (if indicated & available) is mandatory. However, most cases will not progress beyond local envenoming with severe pain. Be aware young children at extra risk for severe envenoming.
Antivenom Therapy
Antivenom is controversial. In some regions it is the standard treatment, but in others is rarely used or avoided. Studies have been conflicting on the effectiveness of antivenom for scorpion sting.
1. Antivenom Code: IAfIPA01
Antivenom Name: Anti-scorpionique (Monovalent)
Manufacturer: Institut Pasteur d_Algerie
Phone: ++213-21-67-25-02
Address: Rue du Docteur Laveran,
16000 Alger
Country: Algeria
Androctonus bicolor "aeneas morph" male (Libya) [ Original photo copyright © Eric Ythier ]
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Androctonus bicolor female (Israel) [ Original photo copyright © Eric Ythier ]
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Androctonus bicolor "aeneas morph" female (Libya) [ Original photo copyright © Eric Ythier ]
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