Wilderness and Rescue Medicine 8th Edition

Wilderness and Rescue Medicine 184

There are a variety of widow spiders found around the world. The systemic symptoms of widow envenomation include muscle cramping (especially in the abdomen), severe pain, numb- ness, and tingling. The development of these symptoms shortly after being in a likely habi- tat should raise the suspicion of a black widow bite. Treatment includes evacuation to medical care if your patient shows signs of critical sys- tem involvement or needs medication to reduce muscle spasm. Antivenom is available but may carry more risk than the venom itself. Symptoms usually resolve over several days but may persist for weeks. Despite its ominous name, death from the bite of a black widow in North America is extremely rare. Brown Recluse The brown recluse is a large spider found in the south-central United States that injects a long- acting tissue toxin causing localized tissue inflam- mation and necrosis.

Brown recluse (Loxosceles reclusa) Scorpions

Scorpions have a wide distribution around the world, but very few species are dangerous. Most scorpion stings are described as similar to, or a bit worse than, your average wasp. Most both- ersome in North America is the bark scorpion (Centruroidies sp.), which employs a potent neurotoxin. Pain may last for hours or days. There is no specific field treatment beyond pain medication. Ice is not indicated. Significant sys- temic symptoms are rare and include agitation and respiratory paralysis; these should prompt an evacuation to medical care. An antivenom is available, but it is a high-risk treatment owing to the incidence of serum sickness and anaphy- laxis. No fatalities fromCentruroidies stings have been reported in the United States, and very rarely elsewhere.

The initial bite may go unnoticed, with a pustule developing several days later. This is often mis- taken for an infection caused by a splinter or other foreign body. It does not respond to incision and drainage or to antibiotics. Although many of these envenomations resolve uneventfully, the lesion can continue to progress over days and weeks to involve a large area of tissue destruction that may become secondarily infected. A suspected brown recluse bite should be referred to a surgeon. Many lesions believed to be caused by a brown recluse turn out to be other problems.

Arizona Bark Scorpion under blacklight