Necrotic arachnidism

Anderson EJ (1987) Recognizing the recluse spider bite in children Necrotic arachnidism. The Journal of the Louisiana State Medical Society 139 33-36. 

There are five representative species of the widow spider in the United States. The species are the Black Widow (L. mactans, L. hesperus, L. variolus). Red Widow (L. bishopi), and the Brown Widow (L. geometricus). The five species of Loxosceles documented to produce necrotic bites are L. arizonica, L. deserta, L. laeta, L. reclusa, and L. rufescens. The L. reclusa is responsible for most cases of clinical significance of necrotic arachnidism. 

B. Loxosceles bites are best known for causing slowly healing skin ulcers, a syndrome often called necrotic arachnidism. ... 

Loxosceles. Therapy for necrotic arachnidism has been difficult to evaluate because of the inherent difficulty of accurate diagnosis. 

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