Wilderness: Black Widow and Brown Recluse Spider Bites
- Spider Bite Overview
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Spider Bite Overview
Black widow spiders (Latrodectus mactans) may be black or brown with a leg span of approximately one to two inches. Most can be identified by a red hourglass marking on the abdomen. They are located throughout the United States. Their toxin causes nerve cell dysfunction and muscle cell twitching.
Brown recluse spiders (Loxosceles reclusa) are tan to dark brown with a leg span of approximately 1 inch. Many have a violin-shaped marking on the chest. They are located mainly in the south central United States.
Both species are common in North America and throughout the world. Human contact with these spiders is usually accidental.
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Wilderness: Black Widow and Brown Recluse Spider Bite
Brown Recluse Spider Bite Overview
Most spiders are absolutely harmless to humans. In fact, of the 20,000 different species of spiders that inhabit the Americas, only 60 are capable of biting humans. Within that small group, only four are known to be dangerous to humans: the brown recluse, the black widow, the hobo or aggressive house spider, and the yellow sac spider. Within this select group, only the brown recluse and the black widow spider have ever been associated with significant disease and very rare reports of death.
- Deaths from brown recluse spiders have been reported only in children younger than seven years. Brown recluse spiders are native to the Midwestern and Southeastern states. Documented populations of brown recluse spiders outside these areas are extremely rare. In recent years controversy has arisen over the appearance of brown recluse spiders in California and Florida. At this time most experts agree that the brown recluse is not...
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Spider Envenomations, Brown Recluse »
In the United States, reports of severe envenomations by brown spiders began to appear in the late 1800s, and today, in endemic areas, brown spiders continue to be of significant clinical concern.
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