Vinegaroon exposures reported to a Poison center

Vinegaroons (Mastigoproctus giganteus), also known as whip scorpions, are arachnids commonly found in the southwestern United States, parts of Mexico, and southern Florida. They do not bite, but have special teeth on the inside of the trochanters of the front appendages, used to crush prey. They are best known for having pygidial gland secretions containing 83% acetic acid, which are sprayed upon potential predators. There are no published descriptions of injury to human related to vinegaroon exposures. Our primary aim was to characterize types of exposures and clinical effects reported to a poison center that serves an area indigenous to this animal.

The database from a regional poison center was searched for all cases from 1998 to 2022 regarding human exposures to the vinegaroon. Data captured included age, sex, exposure route, type and duration of symptoms, and part of the body affected.

There were 50 exposures reported, with age range from 5 months to 54 years. Females represented 32 cases, males 17, and one unknown. Bites were more commonly described (36 cases), with 13 cases reported skin exposure to secretions, 3 ocular exposures, and 2 ingestions. Location of injury was upper extremities in 16 cases, lower in 11 cases, and torso in 3 cases. Symptoms were present in 88% and included pain, skin erythema, numbness or tingling, itching, and swelling. Ocular exposure were associated with pain in all 3 cases, with blurred vision in one case; effects lasted 1 h, 17 h, and more than 5 days. Four non-ocular exposures were followed to outcome, with duration of effects ranging from less than 1 h to more than 2 days.

In a large series of vinegaroon exposures, females predominated, with most exposures occurring from skin contact with secretions. The most common symptoms were pain, erythema, numbness, itching, and swelling, which resolved in less than two days. Ocular exposures were associated with more symptoms and longer duration of effects.