Once bitten...

February 5, 2018 6:11 AM

In the absence of suitable antivenom serum, what if anything can one do to ameliorate a poisonous insect bite?

I'm a writer with a horror book under contract. The plot revolves around a newly discovered species of centipede with a venomous bite. One of my main characters gets bitten. There is no antivenom available, and I know they can take many days to prepare. So is there something she can do in the short term to lessen or banish the effects of the venom? If she gets good and drunk, could that denature or "water down" the venom?

posted by Guy_Inamonkeysuit to Science & Nature (14 answers total)

Immediate treatment consists of rinsing the bite site in cold water. If not too painful, ice the bite site. This constricts the blood vessels so the venom does not spread. Also recommended is papain, an enzyme that breaks down protein. Papain can be found in meat tenderizer and papaya. This deactivates the majority of the centipede venom's proteins.

—from Wikipedia
Also perhaps worth noting that centipedes bites are venomous, poisonous is for things you shouldn’t eat, like poison hemlock.
posted by SaltySalticid at 6:19 AM on February 5, 2018 [1 favorite]

Response by poster: Interesting. So what would you do with the meat tenderizer? Spread it on the bite? Ingest it?
posted by Guy_Inamonkeysuit at 6:30 AM on February 5, 2018

There are devices that can be used to suck out as much as possible of the venom. Such as this one. I think that anything that creates a vacuum can help, so in urgent cases I would not hesitate to employ a vacuum cleaner.
posted by Too-Ticky at 6:43 AM on February 5, 2018

I know that for snake bites at least, the extraction tools aren't really effective (PubMed). They do work to get botfly larvae out (PubMed 2). I don't know if they'd work better on a different bite or a different venom - it probably depends somewhat on how the venom actually works.
posted by natabat at 6:56 AM on February 5, 2018 [2 favorites]

Back in the dark ages, I got bit stung by a jellyfish (I've been stung many times over the years, but that was the first one). The beach lifeguards (this was in South Carolina) all had spray bottles filled with water and meat tenderizer that they kept on hand to spray on jellyfish victims.

The last time I got stung they didn't seem to offer the remedy anymore. Whether that's due to issues of effectiveness or liability I have no idea.
posted by sardonyx at 6:56 AM on February 5, 2018

you spread the meat tenderiser (which must contain papain) on the affected area. a lot of venoms are peptides, so papain, a protease, breaks down protein by breaking chemical bonds, and neutralises the venom that way. this doesn't work on all types of venom, but it works on some. it also can reduce inflammation, since our immune responses often involve protein responses.

i would guess it's becoming less commonly offered by beach lifeguards because of liability issues, since people can have an allergic reaction to papain (and might not know they're allergic).
posted by halation at 7:00 AM on February 5, 2018 [2 favorites]

where is the centipede from? I found a study of a chinese centipede's venom that indicated it's made up of combinations of latrotoxin and ion channel inhibitors .

Latrotoxins basically target different types of animals nerve cells. The one that effects vertebrates alpha-latrotoxin, is the one you care about, it causes latrodectism, and there are some notes on treatment.

I would note that if someone or something lived previously from this presumably fatal bite (human or animal), antivenom could be made from their blood. They could also possibly cut the bite out their flesh (or remove a bitten finger before it spreads to the rest of their hand, horror book after all). Finally you could have them be protected, possibly, by some sort of tattoo or scar tissue so they only get a small dose... that would incidentally allow them to use their own blood potentially to create a cure later, but then I'm getting into suggestions for writing and should probably stop.

Papain seems to trigger the sale allergy as latex, and the FDA is cracking down on it because people have been injured by using it, so you might want to stay away from including it.
posted by gryftir at 7:42 AM on February 5, 2018 [2 favorites]

If she gets good and drunk, could that denature or "water down" the venom?

By the time her blood alcohol concentration was high enough to denature the venom proteins it would also be high enough to denature her own body's proteins. And long before that she would die of alcohol poisoning anyway. Getting drunk would also make it difficult to diagnose or treat the effects of the venom.

A high proof alcohol (e.g. 70%) could be applied directly immediately following a bite in an effort to break down some of the venom, similar to papain.

There's evidence that hot water immersion helps with envenomation by marine animals, but it likely does not help bites or stings from terrestrial animals, as at least among snakes their venoms tend to be heat stable well beyond temperatures that a human can withstand even briefly.
posted by jedicus at 9:54 AM on February 5, 2018 [2 favorites]

Ooooh if papain helps, so might bromelain, which is found in pineapple.
posted by infinitewindow at 10:15 AM on February 5, 2018 [1 favorite]

Insect stings are also treated with tobacco - this was the go-to remedy for bee and wasp stings in my youth in rural areas.
posted by ErisLordFreedom at 12:20 PM on February 5, 2018

Also fyi- centipedes aren't insects.
posted by fshgrl at 1:26 PM on February 5, 2018

Glad to know that you're a writer constructing a fictional situation, but just from the info presented before the jump, this XKCD comic came to mind:

https://xkcd.com/582/
posted by NumberSix at 7:44 PM on February 5, 2018

Best answer: I don't know about centipedes, but this question reads very oddly from an Australian first aid POV (where if pretty much anything bites you, you're going to have a bad time). Icing is going to work for the immediate pain but that's just the bite site. If you try to cut out the venom you're just going to annoy the paramedics who'll have to deal with the cut and bleeding as well. Incidentally, the two reasons you aren't supposed to suck out the venom are 1. you're just getting venom in your mouth and 2. hospitals can synthesise antivenom from any remnant in the bite.

Snake and spider venom generally travel through the lymphatic system, not the blood, so immobilisation is the key thing. The Pressure Immobilisation Technique is a gauze bandage to the site of the bite, then lots of elastic roll bandages around and up and down to stop the limb---and it's typically an ankle or foot or hand---from moving the venom. Sling them up, sit them down, tell the patient to do *nothing* and wait for help.

The good news is most healthy people, who don't have other medical issues, aren't likely to die from most bites *if* they get medical attention. Anaphylaxis is the big one to worry about, and anything else that might stop breathing, so is renal failure for anyone with existing kidney problems. But for most people it's just excruciating pain, nausea, light sensitivity, sweating, temporary paralysis, vomiting and loss of bowel control, and a bunch of other unpleasant symptoms.
posted by Fiasco da Gama at 9:22 PM on February 5, 2018 [5 favorites]

My apologies. I've just checked the Australian Resuscitation Council's Guideline on envenomation and PIT which reads:

The Pressure Immobilisation Technique is NOT recommended for the first aid management of:

• other spider bites including redback;
• jellyfish stings;
• fish stings including stonefish bites
• stings by scorpions, centipedes or beetles.

(My italics).

So my comment above doesn't really apply. There's no guidance on what to do if bitten by a centipede, alas...
posted by Fiasco da Gama at 6:54 PM on February 7, 2018