The Chilean Recluse Spider is a venomous spider, Loxosceles laeta, of the family Sicariidae (formerly of the family Loxoscelidae). In Spanish, it (and other South American recluse spiders) is known as araña de rincón, or “spider of the corner”; in Portuguese, as Aranha-marrom or “brown spider”. This spider is considered by many to be the most dangerous of the Recluse Spiders, and its bite is known to frequently result in severe systemic reactions, including death.
Some bites are minor with no necrosis, but a small number produce severe dermonecrotic lesions (cutaneous loxoscelism) or even systemic conditions (viscerocutaneous loxoscelism); sometimes resulting in renal failure and in 3-4% of cases in a recent clinical study in Chile, death.
The serious bites form a necrotising ulcer that destroys soft tissue and may take months and very rarely years to heal, leaving deep scars. The damaged tissue will become gangrenous and eventually slough away. Initially there may be no pain from a bite, but over time the wound may grow to as large as 10 inches (25 cm) in extreme cases.
Bites may take up to seven hours to cause visible damage; more serious systemic effects may occur before this time, as venom of any kind spreads throughout the body in minutes. Deaths have been reported for the related South American species L. intermedia. A longstanding medical condition known by travelers and residents to Chile, the gangrenous spot of Chile, is now believed to be caused by Recluse Spider bites.