Behavioural and epidemiological considerations pertaining to necrotic araneism in southern Africa.

Species of three spider genera are known to cause dermonecrotic lesions in man. The incidence of necrotic araneism caused by species of these genera is a function of their behaviour and their geographical distribution in relation to areas of high human population density. Evidence based on an analysis of 39 diagnosed spider bites suggests that sac spiders (Chiracanthium sp.) are responsible for most spider bites, followed by violin spiders, Loxosceles sp.