Scorpion stings presenting to an emergency department in Singapore with special reference to Isometrus maculatus

We describe the epidemiology and clinical features of scorpion stings presenting to an emergency department in Singapore, including that of the venomous species Isometrus maculatus. A management approach to scorpion stings is proposed.

A retrospective study was done for patients from 2004 to 2009. Cases were identified by searching through emergency department records with ICD code E905, inpatient records, and the hospital toxicology service records. Identification of species was assisted by the Venom and Toxin research program at the National University of Singapore.

A total of 13 cases of scorpion stings were identified. Eleven stings occurred locally, and the remaining 2 stings occurred in neighboring countries. The most common presenting symptoms were pain (92%), numbness (31%), and weakness (23%) confined to the region of the sting. The most common clinical signs recorded were redness (77%), tenderness (77%), and swelling (46%). Only 2 patients had significant alterations of vital signs: 1 had hypertension and the other had hypotension from anaphylaxis. Three patients experienced complications (abscess formation, anaphylaxis, cellulitis) requiring inpatient management. There were no fatalities, and all patients made a good recovery. Three cases were identified to be stings from I maculatus. These cases occurred locally, and mainly had clinical features of pain, redness, and mild regional numbness.

Scorpion stings are uncommon presentations to the emergency department. Most stings cause local reactions that can be managed with supportive treatment. Stings by I maculatus were observed to cause mild, self-limiting effects.