Prospective cohort study of definite spider bites in Australian children

Objectives: To describe the clinical effects of spider bites in a paediatric population and compare to bites in an adult population. Methods: Prospective follow up study of children with definite spider bites where the spiders were immediately collected and expertly identified. Cases were recruited from Australian emergency departments and poison information centres and followed up. Data were collected on circumstances of bites and clinical effects, and compared with similar data from adult spider bites. Results: There were 163 cases (62% male, 38% female; age <16, median age 7 years, interquartile range (IQR): 3-11 years). The median duration of effects was 2 h (IQR 0.25-12 h). The commonest spiders were Huntsman spiders (Sparassidae) and Orb weavers (Araneidae), and comparatively few bites by theridiid spiders, including Red-back spiders. Pain or discomfort occurred in all bites and was severe in 20%. Local effects included puncture marks/bleeding (36%) and red mark/redness (73%). Systemic effects occurred in only 6% of cases. There were no necrotic lesions or ulcers as a consequence of any spider bites (0%; 97.5% CI 0.0-2.2%) and no early allergic reactions or secondary infections. The median duration of clinical effects was shorter than adults, the frequency of severe pain was less than adults and systemic effects were less common in children. Conclusions: Paediatric spider bite causes minor effects in the majority of cases, and is unlikely to cause necrotic ulcers, allergic reactions or infection. The severity and duration of effects differ from adults.