Scorpion sting accidents occur mainly in tropical or subtropical climatic regions, or the spring or summer season^1,2. The clinical picture is extensive due to sting poisoning.³ There is an estimation of 1.2 million poisonings per year.⁴

The poisoning by scorpion sting ranks within the 20 major public health problems in Mexico, primarily affecting children and adults older than 65 years, that is to say, about 300,000 poisonings during a year in the national territory. The incidence rate at the national level was 245.46 per 100,000 habitants in 2010, while in 2015 was 222.33 cases of poisoning by a scorpion sting.² The only specific treatment for this pathology is antivenom.^5-8

Guanajuato is one of the states in Mexico with the highest number of reported cases of poisoning due to scorpion sting, with 43,913 poisonings in 2019, just below Jalisco with 46,554 and Guerrero 45,621 cases.⁹

In Mexico, the mortality estimated was 6,077 deaths between 1979 and 2003¹⁰; 209 deaths from 2006 to 2012 with an incidence rate of 12.4 per 100,000 inhabitants.¹¹

According to the Official Regulations, the clinical practice guidelines (Manual de procedimientos estandarizados para la vigilancia epidemiológica de la intoxicación por picadura de alacrán, Handbook of Standardized Procedures for Epidemiological Surveillance of Scorpion Sting Poisoning) group the signs and symptoms as follows^3,5,11:

• Slight. Local pain, local paresthesias, itching, mild restlessness.
• Moderate. Most of the slight symptoms and persistent crying in children younger than five years old; anguish, headache, epiphora, redness of the eye, itching of the nose, mouth, and throat, sneezing, runny nose, sialorrhea, foreign body sensation in the throat, dysphagia, lingual fasciculations, dry mouth, tachycardia, dyspnea, bloating, abdominal and muscle pain, priapism, vulvar itching.
• Severe. Moderate symptoms and hypertension or arterial hypotension, fever or hypothermia, miosis, mydriasis, photophobia, nystagmus, dyslalia, perioral cyanosis, seizures, temporary amaurosis, bradycardia, arrhythmias, retrosternal pain, oliguria, unconsciousness, multiple organ failure, coma, death.

People younger than five years old, older than 60 years, malnourished, diabetics, hypertensive patients, with nephropathy, and pregnant women are included in the high-risk groups.⁵

In Mexico, there are two scorpion sting poison antivenoms in the market: Birmex^®, manufactured by Laboratorios de Reactivos y Biológicos de México, S.A. de C.V.; and Alacramyn^®, produced by Instituto Bioclon, both with a neutralizing efficacy of 150 LD50 per vial.^12,13

A 70-year-old female enters the Emergency Service at Cruz Roja Mexicana, León Delegation, due to scorpion sting intoxication. She states that it was the first time she had been stung by a scorpion; it took 30 minutes from the accident site until arrival at the hospital. She did not take any home remedies. She has type II diabetes and systemic arterial hypertension; she takes telmisartan and metformin. She denies allergies. Vital signs were 140/90 mmHg blood pressure, 20 breaths per minute, 74 beats per minute, 93% saturation of O₂. A score of 15 on the Glasgow Coma Scale. Signs and symptoms were: low temperature at the site of the sting (32.2°C versus the contralateral site 33.0°C), pain at the site of the sting (distal phalanx of the fourth finger of the right hand), with a score 4/10 on the Visual Analog Scale (VAS) of pain, paresthesia in the stung site. On examination, a normocephalic skull without endostosis or exostosis, isochoric and reflective pupils, hydrated mucosa, no jugular engorgement, no attached murmurs, eutrophic extremities, were observed.

Treatment

According to the current regulations, two vials of F(ab)2 fragments of polyvalent anti-scorpion immunoglobulin (Alacramyn^®) were indicated for present comorbidities. Consistent with our experience, they were stored at room temperature and were intravenously administered at an interval of 30 seconds in a ten cc syringe with a physiological solution at 0.9%.¹⁴ Analgesic was not administered because of the low effectiveness that we have at the institution.¹⁵ The vagal reaction occurred 30 seconds after administration and ceased after 60 seconds. Thirty seconds later, the pain began in the cervical region descending to the sacral region, which persisted for about 60 seconds, remitting on its own.

Discharge Diagnosis

After 120 minutes without requiring a new antidote dose, she was discharged because she did not present any symptom of intoxication, except for pain with a VAS 2/10, heart rate of 72, respiratory rate of 16 and blood pressure of 130 / 80 mmHg, with a diagnosis of remitted scorpion sting poisoning.