Epidemiological and clinical characteristics of scorpionism in Shiraz (2012-2016); development of a clinical severity grading for Iranian scorpion envenomation

Background: Scorpionism is a public health problem in some provinces in Iran. The present study aimed to assess the clinical manifestations of scorpion envenomation in Shiraz and determine a clinical severity grading for Iranian scorpion envenomation in order to suggest a treatment guideline for emergency physicians. Methods: In this analytic retrospective study, all medical charts of patients with scorpion sting admitted in the adult medical toxicology center in Shiraz during July 2012 to July 2016 were assessed. Data regarding the patient's age, gender, sting site, month of envenomation, time of sting, clinical manifestations, vital signs, presence of blood or hemoglobin in urine analysis, duration of admission, color of scorpion, received treatments, and administration of scorpion antivenin were recorded. Results: The scorpions in Shiraz and its suburban area were classified into two groups: yellow scorpions ( Mesobuthus eupeus, Mesobuthus caucasicus , and Compsobuthus matthiesseni) and Hottentotta scorpions (Hottentotta jayakari and Hottentotta zagrosensis). A total of 126 cases of scorpion stings were assessed. About 59% (n=74) were males. The patients aged 8-63 years (mean age, 33.8±11.5 years). About 38.4% (n=48) of the stings occurred during summer. More than 40% of patients (n=51) referred to the emergency department (ED) at night. Localized pain was the most frequent presenting complaint (76.2%). The most frequent general symptom was nausea (6.3%). The most prevalent envenomation site was the lower extremities followed by upper extremities (43.5% and 41.9%, respectively). Based on the clinical severity grading for Iranian scorpion envenomation, 65, 43, and 18 patients (51.6%, 34.1%, and 14.3%) were classified in the grades I, II, and III, respectively. Eighty-one (73%) patients stayed in the ED from 1 to 6 hours, and 30 (27%) patients stayed for >6 hours for observation. Severe localized pain was more prevalent in stings with Hottentotta scorpions than yellow scorpions (P=0.01). The season of envenomation with Hottentotta scorpions was summer in all cases, but envenomation with yellow scorpions was seen throughout the year. All patients received symptomatic treatment, and five were given scorpion antivenin. No death was reported. Conclusion:Hottentotta jayakari is recommended to be listed among the medically important scorpions in Iran. Moreover, scorpion-stung patients in geographical regions where Hemiscorpius lepturus and Androctonus crassicauda are not prevalent may be treated in outpatient departments. The presented grading system can be used for treating patients with scorpion envenomation.