Along came a spider: Medicine's most famous spider eponyms.

Spiders have long been admired for the beauty of their webs. They are celebrated in popular culture as well as in medical eponyms. This contribution provides the historical background for three spider-related eponyms: nevus araneus (spider angioma), arachnodactyly, and the arachnoid mater. Nevus araneus was first named and described by Sir Erasmus Wilson in 1842. Arachnodactyly was described in 1896 by Antoine Marfan using the term pattes d'araignée, which means spider legs. In 1902, Emile Charles Achard proposed the term arachnodactyly for this clinical finding. The arachnoid mater had been named in 1699 by Frederik Ruysch. The clinical management of spider bites from the only two dangerous venomous spiders within the United States, the black widow spider (Latrodectus mactans) and the brown recluse spider (Loxosceles reclusa), is reviewed.