Lynchburg Journal of Medical Science

Lynchburg Journal of Medical Science


Emergency Medicine





Bark Scorpion (Centruroides sculpturatus) is a scorpion in the Greater Phoenix, Arizona, area. Most stings by the scorpion cause self-limited symptoms, such as localized erythema, pain, and pruritus. A few cases can cause more systemic envenomation, including hypersalivation, rotatory nystagmus, and drooling. Recent research has found that antivenom (scorpion) immune f(ab' )2 (equine) injection, when readily available and given promptly, has achieved complete resolution of systemic envenomation. Availability tends to be limited to specific health care centers, such as free-standing and hospital-based emergency rooms. More studies should be done into the availability of this antivenom to be more widely available in the needed areas. More health care centers, such as urgent care centers and self-standing medical practices, should have this medication available to serve the population of this part of the state of Arizona.

Keywords: scorpion sting, antivenom, (scorpion) immune f(ab' )2 (equine) injection, fasciculations, hypersalivation, rotatory nystagmus, Centruroides sculpturatus.


The rugged desert of Maricopa county, Arizona, is the home of the bark scorpion (Centruroides sculpturatus). The scorpion lives in many places, such as homes, backyards, and public areas; most stings are reported, especially in the summer months. The sting is primarily benign. Some cases can cause severe neuromotor disturbances, including fasciculations, rotatory eye movements, and hypersalivation.1 However, most cases of envenomation cause localized, self-limited hypersensitivity reactions, such as pruritus, pain, and redness. Most of these cases seen in the emergency department are usually treated conservatively. An antidote (scorpion) immune f(ab' )2 (equine) injection is available; it hinders the signs and symptoms and yields resolution when given rapidly after presenting neuromotor signs. However, this medication is not readily available at most healthcare facilities, and some emergency centers have antivenom.


Scorpion stings are prevalent complaints seen in the Phoenix, Arizona, area as this is the primary location where the bark scorpion lives. Rarely do these stings cause systemic envenomation; localized reactions, pruritus, and discomfort are the most common symptoms. Localized reaction to the sting on a physical exam is a small barely noticeable puncture; with or without localized erythema, most cases present with pain and paresthesias. Conservative treatment with ibuprofen and diphenhydramine usually resolves the symptoms. On some occasions, however, systemic envenomation is seen ranging from roving eye movements, hypersalivation, and fasciculations. Most stings are usually seen in children; however, severe systemic reactions have been seen in adults, requiring hospitalization. Benzodiazepines have been used in the past with no resolution of symptoms. At this point, specific scorpion antivenom is given, and clinical improvement to a close resolution of systemic symptoms is seen in about 30-60 minutes after rapid administration of antivenom,3 usually 3 vials given intravenously. Antivenom is not widely available at most health care centers but in emergency centers, including free-standing and hospital-based emergency rooms; however, its availability is limited to these types of health settings. Once (scorpion) immune f(ab' )2 (equine) injection is given, significant improvement of symptomatology is observed in about an hour; at this point, the patient can be safely discharged. The use of scorpion antivenom,4 in this part of the country where scorpion stings are a common occurrence not only in the acute care settings but also in the primary care setting, has proven to be beneficial, as most of the systemic reactions secondary to acute envenomation are rapidly hindered when the antidote is administered in a timely manner.

Most patients go home with no further symptoms. About 2.4% of patients, mainly children, present with hypersalivation, fasciculations, and nystagmus. (scorpion) immune f(ab' )2 (equine) injection was used as the antivenom once administered, and complete resolution of neuromotor signs and symptoms was observed in about 30-60 minutes. The Bark scorpion is the only American scorpion that causes systemic envenomation, which requires an antivenom. The southwest Arizona area, mainly Maricopa county, is where the scorpion lives. Stings are a common complaint that is seen almost weekly; the need for antivenom is usually needed in one-third of the stings. The medication must be more readily available in more health care settings, including urgent care centers and primary care doctor's offices. The improvement is seen as fast as 30-60 seconds, with almost complete resolution of symptoms when given in a timely manner.3


Phoenix, Arizona, is a desert area where many venomous creatures live, including the bark scorpion. The sting by the bark scorpion (Centruroides sculpturatus) is quite familiar in Maricopa County of this metropolitan area. The scorpion can be found in almost all cities. Most stings happen right at home, indoors and outdoors; many of the stings that are seen in the emergency department are self-limiting, causing only localized reactions. They are usually treated by non-steroidal anti-inflammatory drugs (NSAIDs) and diphenhydramine, however; certain patients develop systemic reactions that require the appropriate antivenom; such as neuromotor disturbances, tachycardia, nystagmus, fasciculations, hypersalivation. (scorpion) immune f(ab' )2 (equine) injection is the current antivenom that is available; once given, most patients have complete resolution of symptomatology without hypersensitivity reactions which resolve the systemic response quite rapidly when administered promptly.1

Most patients who are stung by the scorpion present with no symptomatology whatsoever, mainly pain and numbness to the sting site.2 About a third to half of the people that are envenomated display symptomatology. (scorpion) immune f(ab' )2 (equine) injection, when given promptly, has a complete resolution of envenomation. Some limitation to these medications is their availability. This medication is not available at the doctor’s office. Antivenom is available in some emergency rooms and free-standing emergency rooms to counteract acute envenomation.

Further research needs to be done, as this is a prevalent complaint not only seen in the emergency setting but quite frequently in the urgent care as well as the primary care doctor’s office. Antivenom (scorpion) immune f(ab' )2 (equine) injection needs to be more widely available in the Phoenix area, as stings and envenomation are widespread complaints that are seen in this community almost daily. Once this medication is more readily available, faster and better patient care can be delivered to this population.


  1. Klotz SA, Yates S, Smith SL, Dudley S, Schmidt JO, Shirazi FM. Scorpion stings and antivenom use in Arizona. Am J Med. 2021;134(8):1034-1038. doi:10.1016/j.amjmed.2021.01.025

  2. Abimannane A, Rameshkumar R, Satheesh P, Mahadevan S. Second dose of scorpion antivenom in children with Indian Red Scorpion (Mesobuthus tamulus) Sting Envenomation. Indian Pediatr. 2018;55(4):315-318.

  3. Nb H, Dn L, Sr K, et al. Centruroides sculpturatus envenomation in three adult patients requiring treatment with antivenom. Clin Toxicol Phila Pa. 2018;56(4). doi:10.1080/15563650.2017.1371310

4 Abroug F, Ouanes-Besbes L, Tilouche N, Elatrous S. Scorpion envenomation: state of the art. Intensive Care Med. 2020;46(3):401-410. doi:10.1007/s00134-020-05924-8


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