Document Type : Case Report


1 Ministry of Health, Muscat, Oman

2 Sultan Qaboos University Hospital, Muscat, Oman

3 Armed Forces Hospital, Muscat, Oman


Background: Scorpion sting envenomation generally causes treatable local and systemic effects; however, in rare cases, the victims might experience sequels in end organs such as central nervous system. In the present paper, a case of relatively self-limiting demyelinating polyneuropathy following a Butidae sting is presented and the possible mechanisms are discussed. 
Case Presentation: A 19-year-old man presented to emergency department of Sultan Qaboos University Hospital, Oman with severe throbbing pain at the base of his right big toe after a scorpion sting. His initial examination revealed normal vital signs and the systemic examinations were unremarkable. Few minutes later, he developed profuse sweating, slurred speech, blurred vision, increased salivation and restlessness. Repetition of measurement of vital signs showed a blood pressure of 160/100 mmHg, heart rate of 140 beat per minute and a respiratory rate of 18 per minute. The patients received scorpion antivenom and cholinergic hyperactivity manifestations. Shortly after, the patient developed involuntary jerky movements in both lower associated with fasciculation. Nerve conduction study was suggestive of demyelinating polyneuropathy. In later days, involuntary jerky movements of lower limbs improved gradually but fasciculation remained. On a follow-up visit after four months, the patient still complained of occasional fasciculation.
Discussion: One explanation for the development of peripheral nerves demyelination in our patient is the inflammatory response triggered by scorpion venom. In addition, this complication can be attributed to direct cytotoxic effects of scorpion venom toxins. Antimicrobial peptides in scorpion venoms are shown to be highly toxic to human cells, which in our case might have damaged the nerve sheet.
Conclusion: Severe scorpion sting envenomation may lead to severe systemic effects and end organ damage. Medical toxicologists should be prepared to diagnose and treat such sequels.


How to cite this article: Alsawafi FA, Alhinai H, Alhattali B, Awad S, Alreesi A, Alshamsi M. Demyelinating Polyneuropathy Following Scorpion Sting Envenomation; a Case Report and Review of Literature. Asia Pac J Med Toxicol 2015;4:161-4.

  1. Warrell DA. Venomous bites, stings, and poisoning. Infect Dis Clin North Am 2012;26:207-23.
  2. Rhalem N, Aghandous R, Chaoui H, Eloufir R, Badrane N, Windy M, et al. Role of the Poison Control Centre of Morocco in the Improvement of Public Health. Asia Pac J Med Toxicol 2013;2:82-6.
  3. Lall SB, Al-Wahaibi SS, Al-Riyami MM, Al-Kharusi K. Profile of acute poisoning cases presenting to health centres and hospitals in Oman. East Mediterr Health J 2003;9:944-54.
  4. Scrimgeour EM, Alexander PC, Rafay A, Al-Riyami K. Antibiotic Handbook. 7th ed. Muscat, Oman: Sultan Qaboos University; 2006. (In Arabic)
  5. Al-Asmari AK, Al-Saif AA, Abdo NM. Morphological identification of scorpion species from Jazan and Al-Medina Al-Munawara regions, Saudi Arabia. J Venom Anim Toxins Incl Trop Dis 2007;13:821-43.
  6. Oman’s Ministry of Health. National Guidelines on Poisoning Management. 1st ed. Muscat, Oman: Ministry of Health; 2009.
  7. Mégarbane B. Toxidrome-based Approach to Common Poisonings. Asia Pac J Med Toxicol 2014;3:2-12.
  8. Bawaskar HS, Bawaskar PH. Scorpion sting: update. J Assoc Physicians India 2012;60:46-55.
  9. Ortiz E, Gurrola GB, Schwartz EF, Possani LD. Scorpion venom components as potential candidates for drug development. Toxicon 2015;93:125-35.
  10. Petricevich VL. Scorpion venom and the inflammatory response. Mediators Inflamm 2010;2010:903295.
  11. Almaaytah A, Tarazi S, Mhaidat NM, Al-Balas Q, Mukattash TL. Mauriporin, a novel cationic a-helical peptide with selective cytotoxic activity against prostate cancer cell lines from the venom of the scorpion Androctonus mauritanicus. Int J Pept Res Ther 2013;19:281-93.
  12. Annane D, Sanquer S, Sébille V, Faye A, Djuranovic D, Raphaël JC, et al. Compartmentalised inducible nitric-oxide synthase activity in septic shock. Lancet 2000;355:1143-8.
  13. Alpay NR, Satar S, Sebe A, Demir M, Topal M. Unusual presentations of scorpion envenomation. Hum Exp Toxicol 2008;27:81-5.
  14. Mohamad IL, Elsayh KI, Mohammad HA, Saad K, Zahran AM, Abdallah AM, et al. Clinical characteristics and outcome of children stung by scorpion. Eur J Pediatr 2014;173:815-8.
  15. Uluğ M, Yaman Y, Yapici F, Can-Uluğ N. Scorpion envenomation in children: an analysis of 99 cases. Turk J Pediatr 2012;54:119-27.
  16. Kishore D, Misra S. Atypical systemic manifestation of scorpion envenomation. J Assoc Physicians India 2009;57:344.
  17. Cavari Y, Lazar I, Shelef I, Sofer S. Lethal brain edema, shock, and coagulopathy after scorpion envenomation. Wilderness Environ Med 2013;24:23-7.
  18. Udayakumar N, Rajendiran C, Srinivasan AV. Cerebrovascular manifestations in scorpion sting: a case series. Indian J Med Sci 2006;60:241-4.
  19. Bosnak M, Ece A, Yolbas I, Bosnak V, Kaplan M, Gurkan F. Scorpion sting envenomation in children in southeast Turkey. Wilderness Environ Med 2009;20:118-24.
  20. National Antivenom and Vaccine Production Center. Polyvalent Scorpion Antivenom [Internet]. 2015 [Cited 23 Jul 2015]. Available from: