An 80-year-old man living in Fréjus in southern France had a cellulitis on the right arm (Figure 1). The patient had no fever, chills, systemic symptoms, or other clinical signs. He felt a slight pain in his arm during the night and while folding his arm, he crushed a spider. The spider's body was immediately recovered and then identified by an entomologist (Figure 2). This typical skin lesion and the spider identification defined this spider bite as an envenomation by a Loxosceles sp. spider.1 The outcome was good after only antalgic treatment.
Skin reaction after a Loxosceles sp. spider bite, showing the red, white, and blue sign (arrows), day 0–13, southern France.
Citation: The American Society of Tropical Medicine and Hygiene 88, 5; 10.4269/ajtmh.12-0339
A, Enlargement of the head and eyes of the spider in B. Identification of the genus Loxosceles was based on six eyes in a curved row on the upper part of the body (prosoma). The species L. rufescens can be suspected because of the geographic location (southern France).
Citation: The American Society of Tropical Medicine and Hygiene 88, 5; 10.4269/ajtmh.12-0339
Infections with herpes zoster virus, herpes simplex virus, and Panton-Valentine toxin-positive Staphylococcus aureus can be misdiagnosed as necrotic arachnidism.1 Nevertheless, the characteristic red, white, and blue sign visible for the first few days (Figure 1) has been associated with loxoscelism. This sign is a consequence of erythema, ischemia, and thrombosis observed from the periphery to the center of the lesion. Loxosceles rufescens was suspected because it is endemic to Mediterranean regions (L. reclusa is not endemic to this region).2
ACKNOWLEDGMENT
We thank Christine Rollard (Département de Systématique et Evolution, Unité de Taxonomie Collection, Section Arthropodes, Muséum National d'Histoire Naturelle, Paris, France) for help in identification of the spider.
- 1.↑
Swanson DL, Vetter RS, 2005. Bites of brown recluse spiders and suspected necrotic arachnidism. N Engl J Med 352: 700–707.
- 2.↑
Yigit N, Bayram A, Ulasoglu D, Danisman T, Corakocal I, Sabcak Z, 2008. Loxosceles spider bite in Turkey (Loxisceles rufescens, Sicariidae, Araneae). J Venom Anim Toxins Incl Trop Dis 14: 178–187.