Road Guarder (Conophis lineatus concolor: Dipsadidae): Case documentation of a clinically significant envenoming

Detailed cases of envenoming by a non-front-fanged snake (NFFS) from North, Central, and South America have had limited representation in the toxicology and toxinology literature. The NFFS, Conophis lineatus, has been reported to deliver bites that resulted in moderately severe envenoming. However, most of these reported cases have been via personal communication, or self-reported and lacking in detailed medical evaluations. Reported here is a case of an amateur naturalist who was traveling in Mexico and was envenomed following extensive protracted bites to both hands from a wild Conophis lineatus concolor. There was rapid development of extensive localized edema, intense pain, and ecchymoses. The patient was transported to a hospital and after arrival the administration of antivenom was considered due to the severe appearance of local symptoms. The patient requested the medical team contact a consultant toxinologist who advised against the administration of antivenom because of the absence of any supporting evidence demonstrating therapeutic benefit in treating envenoming by C. l. concolor. Consequently, all treatments were limited to supportive symptomatic care. Despite the development of prominent localized symptoms, all laboratory evaluations, including coagulopathy assessment values, revealed no remarkable abnormal alterations. The patient was discharged after two days and symptoms gradually resolved with two months of supportive care.