Sunday, December 05, 2010

A different recluse spider

kw: local events, spider bites, photographs

Two weeks ago my wife was talking to a friend and felt something on her ankle. She brushed it off and thought no more about it. Within a couple of hours she began to get redness, and then a blister, where she'd "felt something". We concluded that it was probably a spider bite. Later she saw an injured spider at the other end of the room and stomped it. I put it in a cup and took this picture. I didn't think to photograph the blister (but just wait...).

By morning the blister was more than 1cm long and almost a cm wide, and almost as high. It looked a lot like the larger blister caused by a Brown Recluse spider (the dreaded "fiddleback"), which I saw forty years ago when someone I knew then was bitten. That blister was half the size of a banana (10x3x1.5cm). Fortunately, the cytotoxic venom of this spider is not as strong. This appears to be a different species of Recluse spider, however, but I haven't yet found out which.

My wife saw her doctor later that day. The blister was drained and she got a shot of cortisone to reduce the reaction. It has been slow to heal, however. Cytotoxic spider venoms cause necropathy of the tissues, and there is no medicine for that.

This is how the now-dried blister looks at present. We used both Betadine and an antibiotic ointment on it, with protective band-aids over it, until just yesterday. I expect it will be several more days before the skin underneath heals and the dried blister sloughs off.

In the Wikipedia article Brown Recluse Spider, it is stated, "Despite rumors to the contrary, the brown recluse spider has not established itself in California..." This is nonsense. The fiddlebacks that I saw, the the bite that I witnessed, were in Alhambra, California in 1971. There were thousands of them living under the church I attended in Sierra Madre, and dozens living in the vines of a large stand of ivy on the fence next to my yard, where my friend was bitten. I am very familiar with Loxosceles reclusa.

The specimen pictured above is clearly not a fiddleback, and probably not even of genus Loxosceles, but I suspect it is of the same family, the Sicariidae. It has cytotoxic venom about 1/10 as toxic as the brown recluse, and with a very similar mode of tissue destruction.

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