Spider Bite!

My sincerest apologies for beginning your week with a picture of two festering arachnid bites, but that’s what Mondays are for.

These particular arachnid bites belong to UCSD alumni pal Professor Nic, who is visiting us from Canada, the greatest of nations. The bites sent him to the very same Kaiser emergency room that saved Kelly’s life last year. Unfortunately, modern medicine lacks any kind of test that would reveal the scientific name of the perpetrator.

Kelly and I immediately pinned the blame on the infamous Brown Recluse spider (Loxosceles reclusa). But, according to the LA County Natural History Museum’s extraordinarily useful book Insects of the Los Angeles Basin, the Los Angeles basin has no brown recluses in residence. According to that same book, the most likely perp is the Long-legged Sac spider (Cheiracanthium species).

When disturbed they draw the pair of forelegs back and in, forming a cage around the body . . . These spiders have relatively strong, long fangs and have been known to bite humans, causing a wound that is painful and slow to heal.

Professor Nic captured a photo, in his CorianĀ® bejeweled Airbnb, of the likely perp when he got back from the ER and it looks exactly like the Long-legged Sac spider in the NHM book. Don’t worry, he later released it to the hipster wilds of Echo Park.

Unlike the Brown Recluse, Long-legged sac spiders employ reputation management consultants to keep their nefarious activities out of the news. They live in the corners of rooms and even, according to the NHM book, take up residence in household appliances. So dust out that Vitamix periodically!

Lest we fall into a spider hating hole, allow me to close with some of my own, unpaid spider reputation management. I believe that we should give our our children plush, stuffed spider toys for Christmas instead of teddy bears to instill in them a love of all things Araneae. Spiders are a vital part of the web of life (pun intended) . We should cast off our fear of them and respect the work they do in keeping down the population of other insects. In Southern California the only spider to treat with caution and respect is the Western Black Widow (Latrodectus hesperus). While a spider bite from a Long-legged Sac spider is painful, it’s not going to cause serious consequences.

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9 Comments

  1. Some years ago, my wife was bitten on the leg by a Yellow Sac Spider. This is a very small spider – less than 1/4 inch long – that is a common inhabitant of houses round here (Ontario). She got a large necrotic lesion, covered in little blisters followed by a sloughing of the skin. She still has a scar from it.

    The local poison control people had never heard of this, so referred it to a veterinary school, who gave us full details. Although not as serious as Brown Recluse bites – mainly because the spider is so small, with less venom – it is still rather nasty and needs to be treated in case a secondary infection sets in.

  2. While bites from the spiders that you discussed may not cause serious problems for most people, what are the possibilities of adverse reactions from the very young, the very old, and those with allergies to insect and spider venom?

  3. I am allergic to insect bites. one October about 13 years ago, I had a swelling in my leg above the ankle after going to a Halloween party where I sat outdoors in a lawn chair that had been store for a month. The place that swelled on my lower leg was about five inches in diameter, hot and red. This continued for three months with a fever every morning that left my hair drenched. Aspirin would not bring down the fever. But, it subsided after an hour each morning.

    No, I did not go to doctor or ER. I should have, but I was busy and working. I just looked like a menopausal woman sweating profusely.

    I have no idea what bit me, but there was a little hole in my leg.

  4. The effect of a spider bite depends on the species and the type of venom.

    Black Widow spiders inject a neurotoxin that affects the nervous system. The symptoms can include blurring vision, cramps, tremors difficulty in breathing. Obviously, this can be serious and requires immediate medical attention as death from suffocation tends to be permanent.

    Brown Recluse spiders and the Sac spiders inject a necrotoxin that destroys tissue. The symptoms can include large, blackish patches on the skin as the surface capillaries are destroyed and blood leaks out. Eventually, the damaged tissue will slough off, possibly leaving large ulcerated areas that are open to nasty secondary infection. This too requires medical attention, although perhaps not as urgently as with a neurotoxin.

    The image shows the early effects of a necrotoxin. Not much can be done except dressing the area and monitoring for infection. Antibiotics may lessen the likelihood of this. With luck, only some skin will be lost.

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