Brown recluse spider. In this third post on spiders (previous ones on the tarantula and black widow spider here), we’ll talk about the brown recluse spider. Like the black widow spider, the brown recluse spider also has a unique marking on its body. It’s a tan spider with a violin-shaped marking on its belly. That’s where the cuteness stops for me though.
The brown recluse spider bite is another serious spider bite. While the initial bite can be completely painless, it can be followed with a “red, white, and blue sign” where the skin initially becomes inflamed, then white from lack of blood flow, and then blue as the tissues suffocate without blood and oxygen. The skin can break down causing necrosis (death of the skin). Additionally, the toxin that the brown recluse injects, sphingomyelinase D (a phospholipase), can lead to destruction of your red blood cells, causing a condition called hemolytic anemia. It can also cause destruction of another cell call the platelet (leading to thrombocytopenia). Bites may be especially serious in kids. In short, suspect a brown recluse spider bite? It can lead to badness. Get medical help!
With a bold bright red hourglass on its belly against a shiny black background, the black widow spider is all business. Thus, when the black widow spider attacks… well, you better hope it doesn’t!
As a quick aside, how did the black widow spider get its name? The female black widow spider was reported to eat its male mate after mating. In reality, it does not always do this.
When folks think of spider bites, they often imagine deadly spider bites. In reality, the majority of spider bites are not life threatening. However, the black widow spider bite is one of the more serious spider bites.
The black widow spider, also formidably known as Latrodectus mactans, can release a toxin called alpha-latrotoxin. This causes your nerve cells (aka neurons) to depolarize. Bites can lead to pain and swelling at the site of the bite but also fever, chills, nausea, vomiting, muscle pain, cramps, spasms and abdominal pain. Needless to say, these are indications to get medical help.
People often come into the clinic worried about spider bites. While the majority of these concerns turn out not to be spider bites, it does raise the question of what sorts of medical conditions spiders can cause. In the United States, tarantulas (shown on the left) are one type of spider that may be found in the wild and as pets. While tarantulas can bite, a more common form of defense is for the tarantula to throw its hairs at a predator (e.g. at you if it thinks you’re going to attack it!) These hairs have little barbs and are urticating, meaning they can cause urticaria (a fancy word for hives or wheals).
These little barbed hairs can lodge in the skin and cause wheals or, they can also lodge into the eye. When they lodge in the eye, these tarantula hairs cause a condition called ophthalmia nodosa. These barbs in the eye cause the eye to get inflamed and could actually lead to vision loss if severe enough.
Needless to say, if you believe you’ve been attacked by a tarantula, you should probably get checked out. More on other spiders (e.g. black widow, brown recluse, etc.) in future posts.