Medscape is available in 5 Language Editions – Choose your Edition here.


Scorpion Envenomation Workup

  • Author: David Cheng, MD; Chief Editor: Joe Alcock, MD, MS  more...
Updated: Apr 22, 2016

Laboratory Studies

Scorpion envenomation cases vary from those requiring no laboratory tests to scenarios requiring extensive hematologic, electrolyte, and respiratory analysis.

Obtain a CBC count, as Hemiscorpius lepturus has been shown to cause severe hemolysis. In addition, marked leukocytosis suggests induction of a venom-mediated systemic inflammatory response‒like syndrome.

Electrolyte evaluation is warranted in patients with venom-induced salivation, vomiting, and diarrhea.

Coagulation parameters should be measured for venom-induced defibrination because, at high concentrations, the venom is an anticoagulant. Defibrination syndrome has been reported following Mesobuthus tamulus stings.

Glucose levels should be measured to evaluate for hyperglycemia from liver and pancreas dysfunction.

Troponin and NT-proBNP elevation suggests myocarditis.

Creatine kinase and urinalysis help evaluate for venom-induced excessive motor rhabdomyolysis. Renal failure may occur secondary to hemoglobinuria from hemolysis (after H lepturus sting) or myoglobinuria from rhabdomyolysis

Obtain amylase/lipase values to assess for pancreatitis, which is common, from Tityus trinitatis stings.

Patients may have increased aspartate aminotransferase and alanine aminotransferase levels from venom-induced liver cell destruction.

Increased catecholamine, aldosterone, renin angiotensin, and antidiuretic hormone levels are detected a few hours after the sting. The increased levels persist for 6 hours, after which a gradual decline occurs.

Interleukin (IL)–1 levels are elevated in all envenomations.

High levels of IL-6, interferon-gamma, and granulocyte-macrophage colony-stimulating factor are present in severe envenomations.

Radiolabeled antibodies or immunoenzymatic assays help quantify the serum venom level because an association exists between the clinical signs of envenomation and this level.

Obtain arterial blood gas (ABG) measurements as indicated for respiratory distress or to determine acid/base status.


Imaging Studies

Obtain a chest radiograph in cases of respiratory difficulty. Unilateral pulmonary edema may be seen on chest x-ray films because of the venom effect on pulmonary vascular permeability.

Echocardiography is more sensitive than electrocardiography and creatine kinase assays for assessing myocardial compromise after a scorpion sting. Findings show a diffuse global biventricular hypokinesis with a decreased left and right ventricular ejection fraction of approximately 0.14-0.38. This dysfunction can appear just a few hours after the sting and usually normalizes within 4-8 days. Serial echocardiography findings show that the return of left ventricular function to a normal state correlates to clinical cardiorespiratory improvement.

Color-flow Doppler study findings show mitral incompetence, probably secondary to venom-induced dilated cardiomyopathy.

Myocardial perfusion scintigraphy can also be used to investigate the contractility and perfusion of the cardiac tissue.[24]


Other Tests

Arterial blood gas determinations show a decrease in arterial oxygenation tension and an increase in PCO2 within 15 minutes of the envenomation, findings consistent with mild metabolic acidosis.

Pulmonary artery catheterization findings may include the following:

  • Elevated systemic vascular resistance occurs up to 4 times the normal level, with elevated mean arterial pressure (MAP) of 203 mm Hg.
  • Left ventricular failure produces a MAP of 57-69 mm Hg.
  • Biventricular failure produces a MAP of 47 mm Hg.
  • Low cardiac index occurs with elevated filling pressures.

Perform serial spirometry measurements to help detect impending venom-induced diaphragmatic failure.

Electrocardiography, if indicated, should be performed. ECG changes persist for 10-12 days before normalizing. ECG changes are observed in 63% of children who have been envenomated. Rhythm disturbances are not dose-dependent but are related to the venom composition. Note the following:

  • First-degree block - 10.2%
  • Bundle-branch block - 12.8%
  • Ventricular repolarization abnormalities - 15%
  • T-wave inversion - 39%
  • ST changes - 39%
  • QTc prolongation - 53%
  • Sinus tachycardia - Most common rhythm
  • A possible sequence of ECG changes has been noted. This sequence starts with bizarre, broad-notched, biphasic, peaked T waves with a beat-to-beat variation. This bizarre T wave is followed by the appearance of tiny Q waves and then atrioventricular dissociation with an accelerated junctional rhythm.


Cerebrospinal fluid pleocytosis is evident on spinal tap studies.


Histologic Findings

The local sting site shows mixed inflammatory cell infiltrates with eosinophils scattered among collagen bundles in an edematous dermis. Myocardial changes, which are most prominent at the papillary muscle and subendocardial region, include focal myocardial necrosis; myofibril destruction, especially at the I band; fine fatty deposits in the cardiac muscle fibers; interstitial edema; and increased cellularity, mainly lymphocytes and monocytes. Changes resemble interstitial hypoxia-induced myocarditis caused by large doses of catecholamines.

Contributor Information and Disclosures

David Cheng, MD Associate Professor of Emergency Medicine, Education Director, Associate Emergency Medicine Residency Director, Case Medical Center

David Cheng, MD is a member of the following medical societies: American College of Emergency Physicians, International Society for Mountain Medicine, Council of Emergency Medicine Residency Directors, American Heart Association, National Association of EMS Physicians, Society for Academic Emergency Medicine, Society of Critical Care Medicine, Wilderness Medical Society

Disclosure: Nothing to disclose.


Sean P Bush, MD, FACEP Professor of Emergency Medicine, The Brody School of Medicine at East Carolina University

Sean P Bush, MD, FACEP is a member of the following medical societies: American College of Emergency Physicians, International Society on Toxicology, Society for Academic Emergency Medicine, Wilderness Medical Society

Disclosure: Received honoraria from BTG Inc. for speaking and teaching.

Ramy Yakobi, MD, MBA Medical Director, Department of Emergency Medicine, Beth Israel Medical Center

Ramy Yakobi, MD, MBA is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians

Disclosure: Nothing to disclose.

Charles J Gerardo, MD, FACEP Associate Professor, Department of Surgery, Division of Emergency Medicine, Duke University School of Medicine; Vice Chief of Program Development, Division of Emergency Medicine, Duke University Medical Center

Charles J Gerardo, MD, FACEP is a member of the following medical societies: American College of Emergency Physicians, Society for Academic Emergency Medicine, Council of Emergency Medicine Residency Directors, National Hispanic Medical Association

Disclosure: Received research grant from: BTG International Inc.

Judith A Dattaro, MD, FACEP Assistant Professor of Emergency Medicine in Surgery, Cornell University Medical College; Consulting Staff, Department of Emergency Medicine, Weill-Cornell University Medical Center, New York Presbyterian Hospital

Judith A Dattaro, MD, FACEP is a member of the following medical societies: American Association of Women Emergency Physicians, American College of Emergency Physicians, American Medical Association, Chicago Medical Society, Illinois State Medical Society, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

Joe Alcock, MD, MS Associate Professor, Department of Emergency Medicine, University of New Mexico Health Sciences Center

Joe Alcock, MD, MS is a member of the following medical societies: American Academy of Emergency Medicine

Disclosure: Nothing to disclose.

Additional Contributors

Lisa Kirkland, MD, FACP, FCCM, MSHA Assistant Professor, Department of Internal Medicine, Division of Hospital Medicine, Mayo Clinic; Vice Chair, Department of Critical Care, ANW Intensivists, Abbott Northwestern Hospital

Lisa Kirkland, MD, FACP, FCCM, MSHA is a member of the following medical societies: American College of Physicians, Society of Hospital Medicine, Society of Critical Care Medicine

Disclosure: Nothing to disclose.

  1. Khatony A, Abdi A, Fatahpour T, Towhidi F. The epidemiology of scorpion stings in tropical areas of Kermanshah province, Iran, during 2008 and 2009. J Venom Anim Toxins Incl Trop Dis. 2015. 21:45. [Medline].

  2. Queiroz AM, Sampaio VS, Mendonça I, Fé NF, Sachett J, Ferreira LC, et al. Severity of Scorpion Stings in the Western Brazilian Amazon: A Case-Control Study. PLoS One. 2015. 10 (6):e0128819. [Medline].

  3. Chippaux JP, Goyffon M. Epidemiology of scorpionism: a global appraisal. Acta Trop. 2008 Aug. 107 (2):71-9. [Medline].

  4. van der Meijden A, Coelho P, Rasko M. Variability in venom volume, flow rate and duration in defensive stings of five scorpion species. Toxicon. 2015 Jun 15. 100:60-6. [Medline].

  5. Mowry JB, Spyker DA, Brooks DE, McMillan N, Schauben JL. 2014 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 32nd Annual Report. Clin Toxicol (Phila). 2015 Dec. 53 (10):962-1147. [Medline].

  6. Jahan S, Mohammed Al Saigul A, Abdul Rahim Hamed S. Scorpion stings in Qassim, Saudi Arabia--a 5-year surveillance report. Toxicon. 2007 Aug. 50(2):302-5. [Medline].

  7. Shahbazzadeh D, Amirkhani A, Djadid ND, Bigdeli S, Akbari A, Ahari H. Epidemiological and clinical survey of scorpionism in Khuzestan province, Iran. Toxicon. 2009 Mar 15. 53(4):454-9. [Medline].

  8. Dehghankhalili M, Mobaraki H, Akbarzadeh A, Yazdani R, Nazemi A, Ghaffarpasand F, et al. Clinical and Laboratory Characteristics of Pediatric Scorpion Stings: A Report From Southern Iran. Pediatr Emerg Care. 2015 Nov 2. [Medline].

  9. Bosnak M, Ece A, Yolbas I, Bosnak V, Kaplan M, Gurkan F. Scorpion sting envenomation in children in southeast Turkey. Wilderness Environ Med. 2009 Summer. 20(2):118-24. [Medline].

  10. Ulug M, Yaman Y, Yapici F, Can-Ulug N. Scorpion envenomation in children: an analysis of 99 cases. Turk J Pediatr. 2012 Mar-Apr. 54(2):119-27. [Medline].

  11. Langley RL, Morrow WE. Deaths resulting from animal attacks in the United States. Wilderness Environ Med. 1997 Feb. 8(1):8-16. [Medline].

  12. Boyer L, Heubner K, McNally J, Buchanan P. Death from Centruroides scorpion sting allergy [abstract]. J Toxicol Clin Toxicol. 2001. 39:561-562.

  13. Bawaskar HS, Bawaskar PH. Scorpion sting: update. J Assoc Physicians India. 2012 Jan. 60:46-55. [Medline].

  14. Skolnik AB, Ewald MB. Pediatric scorpion envenomation in the United States: morbidity, mortality, and therapeutic innovations. Pediatr Emerg Care. 2013 Jan. 29(1):98-103; quiz 104-5. [Medline].

  15. Bouaziz M, Bahloul M, Kallel H, Samet M, Ksibi H, Dammak H, et al. Epidemiological, clinical characteristics and outcome of severe scorpion envenomation in South Tunisia: multivariate analysis of 951 cases. Toxicon. 2008 Dec 15. 52(8):918-26. [Medline].

  16. Prasad R, Mishra OP, Pandey N, Singh TB. Scorpion sting envenomation in children: factors affecting the outcome. Indian J Pediatr. 2011 May. 78(5):544-8. [Medline].

  17. Guerra CM, Carvalho LF, Colosimo EA, Freire HB. Analysis of variables related to fatal outcomes of scorpion envenomation in children and adolescents in the state of Minas Gerais, Brazil, from 2001 to 2005. J Pediatr (Rio J). 2008 Nov-Dec. 84(6):509-15. [Medline].

  18. Parma JA, Palladino CM. [Scorpion envenomation in Argentina]. Arch Argent Pediatr. 2010 Apr. 108(2):161-7. [Medline].

  19. Freire-Maia L, Pinto GI, Franco I. Mechanism of the cardiovascular effects produced by purified scorpion toxin in the rat. J Pharmacol Exp Ther. 1974 Jan. 188(1):207-13. [Medline].

  20. Pinto MC, Borboleta LR, Melo MB, Labarrére CR, Melo MM. Tityus fasciolatus envenomation induced cardio-respiratory alterations in rats. Toxicon. 2010 Jun 1. 55(6):1132-7. [Medline].

  21. Bahloul M, Chaari A, Dammak H, Samet M, Chtara K, Chelly H, et al. Pulmonary edema following scorpion envenomation: mechanisms, clinical manifestations, diagnosis and treatment. Int J Cardiol. 2013 Jan 10. 162(2):86-91. [Medline].

  22. Bawaskar HS. Diagnostic cardiac premonitory signs and symptoms of red scorpion sting. Lancet. 1982 Mar 6. 1(8271):552-4. [Medline].

  23. Kaplanoglu M, Helvaci MR. Scorpion stings in pregnant women: an analysis of 11 cases and review of literature. Clin Exp Obstet Gynecol. 2015. 42 (2):228-30. [Medline].

  24. Figueiredo AB, Cupo P, Pintya AO, Caligaris F, Marin-Neto JA, Hering SE. [Assessment of myocardial perfusion and function in victims of scorpion envenomation using gated-SPECT]. Arq Bras Cardiol. 2010 Apr. 94(4):444-51. [Medline].

  25. Nouira S, Boukef R, Nciri N, Haguiga H, Elatrous S, Besbes L, et al. A clinical score predicting the need for hospitalization in scorpion envenomation. Am J Emerg Med. 2007 May. 25 (4):414-9. [Medline].

  26. Aksel G, Güler S, Doğan NÖ, Çorbacioğlu ŞK. A randomized trial comparing intravenous paracetamol, topical lidocaine, and ice application for treatment of pain associated with scorpion stings. Hum Exp Toxicol. 2015 Jun. 34 (6):662-7. [Medline].

  27. Chippaux JP. Emerging options for the management of scorpion stings. Drug Des Devel Ther. 2012. 6:165-73. [Medline].

  28. Boyer LV, Theodorou AA, Berg RA, et al. Antivenom for critically ill children with neurotoxicity from scorpion stings. N Engl J Med. 2009 May 14. 360(20):2090-8. [Medline]. [Full Text].

  29. Natu VS, Kamerkar SB, Geeta K, Vidya K, Natu V, Sane S, et al. Efficacy of anti-scorpion venom serum over prazosin in the management of severe scorpion envenomation. J Postgrad Med. 2010 Oct-Dec. 56(4):275-80. [Medline].

  30. 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 Jan 5. 342:c7136. [Medline]. [Full Text].

  31. Kumar CM, Prasad SV. Echocardiologic evaluation and follow-up of cardiovascular complications in children with scorpion sting in coastal South India. Indian J Crit Care Med. 2015 Jan. 19 (1):42-6. [Medline].

  32. Kumar PM, Krishnamurthy S, Srinivasaraghavan R, Mahadevan S, Harichandrakumar KT. Predictors of Myocardial Dysfunction in Children with Indian Red Scorpion (Mesobuthus tamulus) Sting Envenomation. Indian Pediatr. 2015 Apr. 52 (4):297-301. [Medline].

  33. Tan HH, Mong R. Scorpion stings presenting to an emergency department in Singapore with special reference to Isometrus maculatus. Wilderness Environ Med. 2013 Mar. 24(1):42-7. [Medline].

  34. Abroug F, Souheil E, Ouanes I, Dachraoui F, Fekih-Hassen M, Ouanes Besbes L. Scorpion-related cardiomyopathy: Clinical characteristics, pathophysiology, and treatment. Clin Toxicol (Phila). 2015 Jul. 53 (6):511-8. [Medline].

  35. Sundararaman T, Olithselvan M, Sethuraman KR, Narayan KA. Scorpion envenomation as a risk factor for development of dilated cardiomyopathy. J Assoc Physicians India. 1999 Nov. 47(11):1047-50. [Medline].

  36. Bhoite RR, Bhoite GR, Bagdure DN, Bawaskar HS. Anaphylaxis to scorpion antivenin and its management following envenomation by Indian red scorpion, Mesobuthus tamulus. Indian J Crit Care Med. 2015 Sep. 19 (9):547-9. [Medline].

  37. Gupta BD, Parakh M, Purohit A. Management of scorpion sting: prazosin or dobutamine. J Trop Pediatr. 2010 Apr. 56(2):115-8. [Medline].

  38. Patil SN. A retrospective analysis of a rural set up experience with special reference to dobutamine in prazosin-resistant scorpion sting cases. J Assoc Physicians India. 2009 Apr. 57:301-4. [Medline].

  39. Centruroides (Scorpion) Immune F(ab’)2 (Equine). Prescribing information. Accessed August 9, 2011. [Full Text].

Centruroides limbatus, identified by Scott Stockwell, PhD. A small barb at the base of the stinger may be helpful in identifying Centruroides or Tityus species, although its presence is variable. Photo by Sean Bush, MD.
Centruroides species. Note the slender pincers generally characteristic of scorpions from the family Buthidae. Photo by Sean Bush, MD.
Scorpions from the family Buthidae (which includes almost all of the potentially lethal scorpions) generally can be identified by the triangular sternal plate. In other families of scorpions, this feature is more square or pentagonal. Photo by Sean Bush, MD.
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.