Black widow species (Latrodectus species) envenomation can produce a syndrome characterized by painful muscle rigidity and autonomic disturbances. Symptoms tend to be more severe in young children and adults. We describe black widow spider exposures and treatment in the pediatric age group, and investigate reasons for not using antivenom in severe cases.

All black widow exposures reported to the Rocky Mountain Poison Center between January 1, 2012, and December 31, 2015, were reviewed. Demographic data were recorded. Patients were divided into 2 groups. Group 1: contact through families from their place of residence, public schools and/or cases where patients were not referred to healthcare facilities. Group 2: patient contact through healthcare facilities.

93 patients were included. Forty (43%) calls were in Group 1 and 53 (57%) in Group 2. Symptoms were evident in all victims; 43 (46.2%) were grade 1, 16 (17.2%) grade 2 and 34 (36.5%) grade 3, but only 14 patients (41.1%) of this group received antivenom. Antivenom use was associated with improvement of symptoms within minutes, and all treated patients were discharged within hours, without an analgesic requirement or any complications. Reasons for not receiving antivenom included: skin test positive (2/20), strong history of asthma or allergies (2/20), physician preference (2/20), non-availability of the antivenom at the health care facility (14/20).

In our study, most symptomatic black widow envenomations were minor. Relatively few patients received antivenom, but antivenom use was associated with shorter symptom duration among moderate and major outcome groups.