Suppose you’re down south, outside, maybe bugging out, and you see this cute little caterpillar, maybe an inch or an inch and a half long, crawling along a branch. Maybe you’re curious; or worse yet, your kid or dog decides to pet the ‘furry little thing’. Or maybe you never see it, but find it when putting your hand on some bit of tree without looking first. And then the pain comes …
Some other entries in the PrepperMed 101 series have talked about other health threats you’re more likely to encounter when wandering in the great outdoors than in an urban environment. This one’s about a common threat, not life threatening but miserable-making, to those who live in the southern US, from the Maryland to Mexico, Florida to Texas: Megalopyge opercularis, commonly known as the puss caterpillar or asp caterpillar or wooly slug.
Is this the biggest threat ever? No. But it’s common in some parts of the country, highly unpleasant, can be avoided or the impacts reduced easily if you know how; and much of the advice applies just as well to other bites, stings, and nettle contacts, making it worth knowing about.
Awww, it’s so cute and fuzzy looking…. you really want to NOT TOUCH IT EVER! Colors may range from this pale one through browns and dark red.
More painful than dangerous
This nasty beastie is the larval stage of a really pretty flannel moth. Most years they’re not too abundant, but when conditions are right there can be major outbreaks — there have been a few instances when communities have closed schools in an attempt to keep the kids away from them during an outbreak. The caterpillar favors trees such as citrus, sycamore, elm, and oak; but you can find them other places:
Salty’s story: I was 4 years old, and my parents had given me a big, shiny red tricycle. I loved riding my tricycle around the driveway (we had a long, paved, flat driveway in Fort Walton Beach, Florida). Little Salty would run out of the house, hop onto my trike, and off for laps I would go… I was like Richard Petty at Daytona, not that I had ever heard of him at the time. One day I ran out, hopped down on my trike and felt a searing pain on my leg. I jumped up, and saw that I had sat down with my bare leg on top of a caterpillar.
I can’t say that it was the most painful thing ever, but it’s just about the only memory I have of us living at Fort Walton Beach. Apparently, it caused a huge welt and my mother ended up taking me to the doctor because it started looking and feeling really ugly.
The ‘fur’ is actually a bunch of hollow spines filled with venom. They pierce and inject into any skin they contact very readily. That leads to the second main tip: Apply a strip of tape to the contact area then pull it back off to help remove any spines left in the wound. (The first tip was not to touch anything looking like that.)
The contact area shows up as a red halo, then small blisters form at each puncture site (often filling with bloody fluid). This develops a gridlike pattern of blood blisters that experiences intense pain that comes in waves. The blisters can continue to collect fluid, getting quite sizable. (1) . Untreated, the symptoms can last 4-5 days. Every now and then, a person will have a worse reaction that looks like shock: pale, rapid thready pulse, heavy sweating, wheezy breath.
The blisters can get quite sizable, as you can see.*
Once you’ve done the tape trick, it’s recommended (2) to wash the area with soap and water and cool it. If you have a cool pack or ice, great. If you don’t, a cooling towel, isopropyl alcohol bath, or just wet bandana over it should help (listed in order of helpfulness). Topical corticosteroids (cortisone itch creams), calamine lotion, a slurry of baking soda (my Mom’s favorite for nettles, a similar problem) can help sooth it. The sources suggest addressing the swelling and pain without being very specific about how; but that often includes over the counter pain meds and antihistamines such as diphenhydramine (Benadryl).
If the person gets shocky, an epinephrine injection into the skin was suggested (1). I’m not a physician, so this is not a recommendation; but I will note the emergency inhalers for allergies have similar effects to epinephrine, and if I had one on hand I’d give it to anyone who was having serious wheezing.
1) Neustater, B. R., & Stollman, N. H. (1996). Sting of the puss caterpillar: An unusual cause of acute abdominal pain. Southern Medical Journal, 89(8), 826.
2) Barish, R.A. and Arnold. (2016) Puss moth caterpillar (asp) stings. Merck Manual, Professional Version. https://www.merckmanuals.com/professional/injuries-poisoning/bites-and-stings/puss-moth-caterpillar-asp-stings
*Thanks to the Ghana Emergency Medicine Collaborative for the image
From personal experience these boogers are even worse than you know, I had one drop down from a tree inside my shirt w/o knowing it, after about 10 minutes I felt an itch that grew to an intense burning pain in half a dozen places. These critters also have stingers on their underside, as they crawl about on your skin they stop, inject venom then move on, and the reaction is delayed, but it ends up feeling like a dirty old man is burning you with a lighted cigar all over. A compress of household ammonia offers some relief, meat tenderizer or a tobacco poultice would probably help, too. Likely how those little stinging flying horse/scorpions in the Book of Revelations will feel to us sinners…
Ivy Mike,
There is a cure for those little stinging flying house\scorpions things. If you dont know the cure, let me know and I will be happy to share it with you.