Lonomism is the envenomation caused by accidental contact with Lonomia caterpillars, and this is a public health priority in South America since it is relatively common but remains underestimated. Patients typically develop severe pain at the site of envenomation, followed by dizziness, headache, nausea, vomiting, and abdominal pain. In severe cases, acute kidney injury, stroke, and shock due to volume loss, which can lead to death. Lonomia refers to a genus of venomous caterpillars belonging to the family Saturniidae, which are found primarily in South America. Recent study presents an updated and integrative analysis of reliable global data from 1960 to 2020 on the epidemiology of this envenomation in the whole continent. Treatment of lonomism typically requires inpatient supportive care. Rapid administration of an antilonomic serum developed in Brazil for envenomation by L. obliqua appears effective for reversing coagulation time and may reduce fatalities, although data are limited.