Envenomation due to the bite of Latrodectus mactans or black widow spider in a pediatric patient

Abstract

Background: Envenomation by the bite of Latrodectus mactans or black widow spider in children manifests clinically with high neurotoxicity. Clinical case: 10-year-old male patient, from a rural area, with a 4-hour history of having suffered a spider bite on the back of his right wrist while collecting firewood. He immediately presented intense pain at the site of the bite, chest and abdomen, up to generalized body pain; in addition, nausea, vomiting and bilateral periorbital edema. On physical examination, he also had tachycardia and tachypnea, although he was normotensive and afebrile, with inflammatory changes in the affected wrist, with the presence of a white spot and a hyperemic halo or target shooting injury. Leukocytosis, neutrophilia, lymphopenia was found, with renal and liver function tests without alterations. He was admitted for suspected poisoning from a Latrodectus mactans bite. The treatment was symptomatic and the antivenom monovalent anti-arachnid immunoglobulin was administered, although late due to hospital limitations. The clinical improvement was favorable, with no complications reported. Conclusions: Latrodectus mactans poisoning can produce a wide spectrum of clinical manifestations and alterations in laboratory tests secondary to the immune response, age and the amount of α-latrotoxin inoculated in relation to the proportion of the body surface, which could put at risk the patient's life. The authors recommend, if a pediatric patient is suspected of being poisoned by this arachnid, immediately refer them to an emergency department.