Hemostatic disorders induced by skin contact with Lonomia obliqua (Lepidoptera, Saturniidae) caterpillars

Patients envenomed by Lonomia sp caterpillars initially experience a mild burning pain, headache, nausea, vomiting, and skin and mucosal hemorrhages. Some patients can rapidly progress to a severe coagulopathy that presents as visceral or intracerebral hemorrhaging. We studied the hemostatic alterations that occurred in 14 patients who were envenomed by Lonomia obliqua in Southern Brazil and presented at the Hospital São Vicente de Paulo (Passo Fundo, RS), Brazil during the summers of 1993 and 1994 when Lonomia antivenom was not yet available for treatment. The patients were classified into to 4 clinical groups: 0 (two patients), I (eight patients), II (two patients), and III (two patients). The patients were admitted to the hospital between 4 hours and five days after contact with the caterpillars. In this study, the coagulation parameters of the patients were followed up for up to 172 hours after the accidents. The patients received no treatment with the exceptions of two patients who received blood transfusions and antifibrinolytic treatment. The observed abnormalities related to blood coagulation and fibrinolytic factors were similar regardless of the severity of the bleeding symptoms. These findings suggest that alterations in hemostatic parameters without thrombocytopenia are not predictors of the seriousness of such accidents. Thus, consumptive disorder and reactive fibrinolysis are not proportional to mild coagulopathy. Furthermore, these patients recovered. The hemostatic parameters of most of the patients normalized between 96 and 120 h after the accident.