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Trees/honey locust thorn poison


russ wrote at 2009-12-01 07:07:42
i don't except your answer to gary blakes question, i have been trimming tree prof. since 1987  and i have always felt very sick in my whole body, and my joints in what ever extremity i get poked have always , very extremely hurts, like my joints are going to freeze up. but no one has ever ever known or shared the same feelings till i read garys question, with me the pain starts about 10 or so min. after the poke, and believe it or not i just got poked above the knee cap, its 3 hours later and i can't bend that knee and i feel very sick. but i know that it will go away, there is a poison or something in the needles to effect me that fast?

jeff carr wrote at 2010-01-30 20:35:34
i was just poked in the wrist with a spin from a honey locast tree, and within 1-2 min's i was not able to move my wrist ore fingers without extreme pain.  

patterson wrote at 2010-03-13 00:26:50
I often get punctures and scratches from multiflora rose thorns, raspberry spines and mile-a-minute vine; no reaction. Yesterday, though, I received a shallow puncture from a black locust thorn. Nothing broke off in my hand. The pain grew rapidly and the spot quickly swelled to an inch in diameter and immobilized my hand at the knuckles (WAY too rapid for an infection). Thirty-two hours later, it's still swollen, hot, red and painful.

MEG wrote at 2010-04-06 00:45:53
I would hope someone conducts further study of these thorns, as I've been suffering symptoms for 5 months.  I started with my general physician for a tetanus shot and antibiotics. The lack of a response led me to an infectious disease specialist who prescribed another anti-biotic and prednesone.  That seemed to get me almost back to normal, but 3 1/2 weeks after the puncture my pain and swelling returned.  Now my knee, calf and foot were very swollen and painful.  My next step was an orthopedic surgeon who scoped the knee, relieving some fluid and confirming that no internal damage or thorn remnants were found.  Physical therapy followed, but the swelling remained.  The surgeon then drained the fluid, which was clear, and injected cortisone.  This allowed me to rebuild the muscles in the leg with more therapy, but the swelling came back.  Now, almost 5 months after the wound, I'm almost back to the original condition.  I'm scheduled to see an arthritis specialist in 3 weeks.  There has to be a better explanation to help those of us who have experienced this painful reaction to "non-toxic" thorns.

thorn trees yuck wrote at 2010-04-08 15:25:28
My husband got stuck on our farm yesterday..about two hours his finger was so swollen he could not move it ....I hate those nasty thorn trees the thorns even puncture tires...but I agree with you there has to be something to the swelling no time for festering or infection .It is really weird.

scooby wrote at 2010-11-13 18:15:19
i have to agree with the questioner - i too have been 'reacted' by a poke by a locust spine.  you don't get a reaction of infection nearly as quick as the poke location swells.  my suspicion is a combination of both.

CJ Fuller wrote at 2011-01-30 17:13:30
In the chapter on Honey Locust, in the book Arboretum America by Diana Beresford-Kroeger, she says that two species of honey locust, Gleditsia Triacanthos (common honey locust) and G. sinensis (Chinese honey locust) have spines that are "counterirritant.  They are highly antibacterial and antifungal.  Unlike all other thorns, if used as a tissue probe, they will go in and come out cleanly without causing infection." p. 72

Hammer wrote at 2011-04-25 18:03:50
When i was about eleven years old, i was cutting wood for our house, and I fell off the bed of a truck. We were cutting black locust trees, and i fell on one and it went straight through my knee. It didn't hurt right away, but later that night it became unbearable. I woke up the next morning and my knee was the size of a canelope! I had surgery twice on it, and was given antibiotics for some rare bone infection I can't remember the name to. I took the antibiotice for 6 months. What is the name of this infection? O_o

scottrece wrote at 2011-05-09 02:51:51
I was poked by a honey locust thorn between two knuckles on my hand earlier today and at this point a few hours later I can barely open my hand and extend my fingers due to the pain.  I don't think there is any of the thorn left inside and the most painful part is actually the knuckle itself near the poke point.  It has swollen a bit, but not to an extreme.  Very painful and am searching the web to find out how dangerous this is.  Just took a couple of Benedryl and hope this helps.  Will be steering well clear of these buggers next time.

GG wrote at 2011-05-23 02:38:57
I am a 57 year old woman who was imbedded by a Locust Tree thorn around 2006 in Kansas at a state park, the thorn broke off into the upper most bone of my first finger, I being a previous hospital worker, immediately cleansed the wound and put antibiotic ointment and bandage on it, that was in the late afternoon, by 2:00 am I was in excruiating pain and had to be taken to the emergency room at which point they ex-rayed and said that part of the thorn was into the bone and that they could not remove the all of it, less than 6 months later I was diagnosed with crippling arthritis and fibromialgia....I was perfectly healthy before this incident. I still have part of the thorn imbedded in my finger which has deformed all three joints of my first finger and am still in pain every day over my intire body, Thus my experience with the NON-POISONOUS Locust Tree.

B.A.H wrote at 2011-06-15 04:41:50
I was poked by a thorn at the bottom of my pinky finger. It was sore, but thought nothing of it. About 2 hours after being poked through my gloves, the intense pain set in. I was up all night and eventually took some pain pills just to get the pain under control. This did not last long. As the hours went on, my finger and half my hand was so swollen, every time I moved it was unbearable. The pain radiated up to my elbow. I have also experienced flu like symptoms for the first 24 hours. Now I am at 48+ hours and the pain is finally under control and I can almost make a fist. With all the stories of this "non-toxic thorn", it is hard to believe there isn't something more documented about these dangerous trees. I even went to the doctor because the pain was so intense. I knew more about the tree/thorn than the doctor did based on research on the internet. I did receive an antibiotic just in case and something to help with the pain.  

dktm wrote at 2011-07-05 03:56:01
I had a thorn removed from my upper arm this past weekend, the result of a bike accident that ended against a Locust tree trunk.  No swelling or pain whatsoever, in fact, the smooth surface and sharp point of the thorn resulted in a very clean wound and no small bits left behind when it was removed.  The doc did comment, however, that puncture wounds can be rough because all sorts of bacteria commonly found on the skin can be introduced to the deeper layers of the skin and underlying tissue where they can cause all sorts of problems.  Perhaps this is the source of unexplained discomfort mentioned by others here.

Gina Roberts wrote at 2011-07-26 20:27:14
I agree with Mr. Blake.  I also have lived all of my 43 years on a farm in Missouri that is full of both honey and black locust trees.  I have been stabbed many times while fencing or clearing brush and it always results in redness, pain, tenderness and swelling.  Any Missouri "native" will tell you that there is poison in the those thorns.  I'm certainly no scientist, but I can tell you from experience that it sure feels like poison or toxins to me.  I have absolutely no other allergies, so I don't believe it is an allergic reaction.  Also, I have had horses and cattle get stabbed by those same thorns with the same signs and symptoms.  I always thoroughly wash the area and cleanse it with peroxide and put antibiotic ointment on it as soon as possible.  This has never prevented the symptoms and so seems silly and I have quit doing it.  However, my opinion is that with no results from my "treatment", I do not believe it is an infection either.  Gina Roberts

devin ohio wrote at 2011-09-05 08:46:07
i got stuck 3 weeks ago by a baby black locust tree the thorn was any about qtr inch long and it stuck in my knuckle for about 2 hrs b4 i noticed it was in there.. went to the dr 2 weeks later they said it was a minor infection gave me antibiotics to take for a week 54 pills lol... well it still not better hurts like hell to move or hold any thing in my hand now.. went back today and the dr is sending me to the othro to see whats goin on i guess idk its hurts tho

new buckeye wrote at 2011-09-21 03:16:25
I can't believe all that I am reading, I just moved into a home in central Ohio and have a large honeylocust in my backyard. I got poked in the first joint of my pinky finger 3 days ago. It was so swollen I couldn't bend it. I keep looking for a splinter, but nothing is in there. My whole finger is still swollen and tender. There has to be more to all these stories than just dirt on the end of the thorn.

Tim Limbert wrote at 2011-09-27 14:38:18
Interesting.  I was clearing some brush just the other day, and got stuck with a honey locust thorn on the back of my right ankle.  Just a small jab, with a tiny hole and no parts of the thorn left behind.  By the end of the day, the ankle was painful and badly swollen.  Now, three days later, it hasn't begun to get better.  My wife and I have both experienced these sorts of symptoms every time we're stuck with one of those thorns.  We get poked and scraped with all sorts of stuff while clearing brush, and this never happens except with the honey locust thorns.  I'll buy that there's no evidence of toxin in the honey locust thorns, but there's SOMETHING that causes a rapid and painful reaction.

Black Locust Thorn Pricked wrote at 2011-10-03 19:18:47
Hello, I am having the same effects the gentleman posted about. I was stuck two times this morning and my finger joint is swelling as well as the knee area. Having been in horticultural/garden work for many years, I have been stuck by a variety of thorns, all types of roses, raspberries, blackberries, etc. I have never had I reaction like this to any other thorn prick (I was also a florist). Although you have some research on the subject, it seems worthwhile to look deeper because there seems to be something else happening if so many people have the same peculiar symptoms associated with this thorn prick.

Sick of these thorns wrote at 2011-10-07 02:56:35
WOW so many people with same prob but still no answer. I got stuck by a honey suckle thorn in my pointer 3-4 weeks ago and still have joint pain . And once again today got stabbed in my other finger and now the same reaction only this time it seems the rest of my right hand/joints are very sore almost sometimes like I shut my hand in a door. Must agree with everyone else that there has to be some better explanation.

Greg in VA wrote at 2011-12-05 17:33:14
Jim I think you are totally wrong about this one.  I have a locust tree in my yard and yesterday got poked pretty deep in the end of a finger and a shallower poke near the second knuckle, and it was nbd at the time.  Within a few hours I was experiencing a surprising amount of joint pain in that finger which has since spread through my hand and into my wrist.  There is some swelling but no heat and redness as you would get in an infection.  I think this is unquestionably some kind of toxin transmitted through the poke with the thorn.  Contrary to your answer, Black locusts are known to be toxic, all parts of the tree except the flowers and it seems certain given the experiences reported here that there is an unknown mechanism for transmitting some of that toxin through the thorn.  This hurts amazingly bad for a little poke, and I'm cutting that tree down ASAP.

pat thomas wrote at 2012-01-04 18:34:23
in 1998 or 99  my husband and i  got pricked multiple times by a locust tree thorns. i got a thorn in my finger. it became swollen and infected  doctor said he could cut it out i kept it wrapped because it was so infected it looked horrible i accidentally hit it on something and it popped threw the skin. the nail on that finger has a deep groove in the middle and still wont grow right.i havent been right since. i take pain meds 3 or 4 times a day i have every dx from arthritis to fibro i do have  spine issues anyway. whole body pain swollen joints some days i cant stand to touch anything  i found this site on accident  maybe i can start from here does anybody have any more info about this thorn and long term damage 419 6217731 i dont work anymore

M. Giesler wrote at 2012-01-10 12:46:03
I have to agree that there does seem to be something special about the prick of a honey locust thorn. On each occasion that I have experienced this, the site of the injury does just what Mr. Blake described - initially, slight discomfort, but within 24 hours, extreme swelling and much greater pain than at actual time of injury. I can remember four such instances, with the most recent being this past weekend. A day after catching my thumb on one of these thorns, the thumb was swollen to the point that I couldn't bend it and the pain was to the extent that even slight contact was excruciating.  Nonetheless, I did get antibiotic ointment and a bandage on it before going to sleep. Upon waking, the swelling has decreased significantly and the pain is certainly tolerable. The point is, on the 4 occasions I have experienced this same injury, it follows the exact progression I have just described regardless of location on the body. That honey locust is not the normal thorn.

Hate.that.tree wrote at 2012-05-23 05:01:46
Just wanted to post so people know how serious these thorns can be. My husband was poked in the knuckle while doing yard work six months ago. The finger swelled and he felt sick with nausea and fever. By morning he felt better but the finger slowly felt stiffer and stiffer and got more and more swollen. After reading a few things on the web he decided it was causing something arthritis-like and ignored it. Eventually it couldn't be ignored and he saw a doctor who did an x-ray and MRI. His diagnosis is bone infection from that dumb thorn and will most likely lose the finger altogether because he thought it was harmless irritation. See your doctor. We are learning the hard way. These honey locust thorns really should be classified differently.  

Nineleft wrote at 2012-06-07 02:34:18
I agree that there is SOMETHING in the honeylocust thorns also. Two days ago, I was wading in a river to find a good fishing hole.. I had to get out and travel through the woods a bit ... I lost my footing and got jabbed in the wrist by a honeylocust thorn.. No part of the  thorn was broken off that I could see... But I felt an IMMEDIATE burning pain throughout my hand and wrist... Within 30 minutes my wrist and fingers were swollen and immobile... I couldn't even grip my fishing pole.. I went home and cleaned it thoroughly and applied neosporin. That night and the next day the pain became so unbearable I went to an emergency room to have it looked at... Doc gave me a steroid shot and started me on antibiotics...  Two days have passed and now I can almost make a fist without grimacing... ALL of the joints in my hand were stiff and extremely painful. I will steer clear of those honeylocust trees from now on...  

jz@naugustasc wrote at 2012-07-14 11:30:21
I found this blog while searching for information about chronic swollen joints after a thorn prick.  I was digging up a bothersome flowering quince bush in my yard over a month ago when I broke off a thorn in my pinky knuckle.  I pulled out the thorn completely and forgot about it.  About 2 hours later I was in excruciating pain.  For the next several days, my pinky stayed swollen and I could not even bend my finger.  The swelling and joint movement have improved to almost normal some days, but other days the swelling and joint stiffness are almost as bad as ever.  I am a nurse and recognize that these are not symptoms of an infection.  I cannot believe there is not more information/answers available about these toxic thorn pricks.

SarahLynn wrote at 2012-07-18 00:42:49
After a black locust pruning session (to train for lumber harvest) I noticed that the prick I got on my finger is very sore and swollen. I have consulted all my resources and have come up with no details except that Robinia pseudoacacia is available as a homeopathic remedy for headaches and stomach problems....

it is also valuable for:

very straight-growing rot-resistant wood supply


Growing living fences

LeAnne Conway from Ohio wrote at 2012-09-06 21:55:34
I disagree with your position.  I have gotten stuck by this nasty thorn twice.  Neither time did I have a piece break off in my skin.  Both times, it was a clean entry point. Today is my most painful reaction.  I can't even see the entry point but my middle finger is in such pain I have to hold it up so the blood flow does not cause additional painful pressure.  The pain has started to spread to my ring finger as well. At this point, I cannot use my left hand without tremendous pain. I have read several entries of people who have the same reaction. My pain began within a few hours of contact with the thorn. I was concerned because of the intense pain and looked for answers on the internet.  To my dismay there thorn is called non-poisonous but my reaction is a definite reaction to the thorn and not a reaction to the dirt on the thorn.  It became painful quickly and without redness.  It is swollen and the joint pain is very uncomfortable.  I took Benedryl a few hours ago hoping to ease the pain and keep the poison from spreading to the rest of my hand. It seems that the Benedryl has made some difference because the pain has stayed constant without increasing pain. I would appreciate feedback.  

Kari64 wrote at 2012-09-10 21:10:13
We have had the same reaction with honey locust thorns.  The area affected swells and is very painful.  My husband got jabbed in the knee and it was swollen and sore for several days.  I stepped on one yesterday--it went through my shoe and into my foot--I pulled it out and it is very painful to walk on.  

This type of reaction occurs every time we happen to get a jab from one of these thorns.

Paul in Kentucky wrote at 2012-10-01 12:52:44
I found this discussion by searching "black locust thorn painful injury." Two days ago I received a minor punch in my knee from a Black Locust thorn while manually removing saplings from an old field; the thorn did not break off. Within an hour the area was painful and stiff; by nightfall my knee was swollen. Now my knee is still stiff and "touch-sensitive," but the swelling is down. On previous occasions I have had painful localized reactions to Honeylocust thorns that seemed to be all out of proportion to the seriousness of the prickle. This time the Black Locust got me in the knee cap and the results were more debilitating.

North Texas wrote at 2012-10-10 03:32:31
I have locust thorn trees and have been poked by the thorns many times. They always seem to hurt more/longer than other types of thorns. If you have ever been finned by a catfish, the effect seems to be the same. I did read a doctor's article about him/her getting poked by a sticker in a joint and being worried about some plant arthritis that can result if any small particles of the thorn get lodged in your joint.  

Kentucky Romper wrote at 2012-11-13 03:25:37
I was Deer hunting yesterday and as it became dark, made my way out of the woods.  I made my way through some thick brush by the time i made it back to the 4 wheeler.  Once back at my house, i noticed a black thorn broke off in my elbow.  I pulled it out and by morning I became red, swollen, and hot.  Also my elbow is in some discomfort when I bend it or apply any pressure on the thorn site.  Im pretty sure I came in contact with a Black Locust thorn but not entirely sure.  Im just curious on how long my elbow is going to feel like I have arthritis in it?

P.J.D. wrote at 2012-11-14 02:19:18
I too have Honey Locust trees on my land. Three days ago a thorn poked my foot and my foot swelled up painfully. This is not the first time this has happened. I have been poked by other thorns, (such as rose etc), and never have had a reaction such as this. Maybe some people are more allergic to these thorns than others?

P.J.D. wrote at 2012-11-14 02:49:12
I was poked three days ago on my foot. I first thought I stepped on a stick so didn't look at what poked me. However, within about ten minutes pain started radiating and that's when I knew what it was I got poked with. It is a different kind of pain. I know, for it has happened before. By that evening my foot swelled up, started turning red half way up the top of my foot and was painful to the touch. It was filled with heat and I could hardly walk. The wound was clean so I know there was no residue from the thorn or dirt. Neosporin was applied plus I used peroxide. It still is swollen by day three but it seems to be improving. The red is going away as is some of the swelling. The pain all over my foot is less but still hurts to the touch. There is more to this thorn and I wish someone would research it.  

Ihatethattree wrote at 2012-11-30 16:43:47
I don't know what a "locust thorn" is....but I wound up here, because of a question I asked google.

I have lived in this house for twelve years and have an emotional relashionship with the Bastard Lemon Tree. There are three of them (2 1/2 long story) are Bastards but it's not their fault. It's just nature...BUT..

They have these 1/8"-4" spears that SUCK!!! Most of my cussing has taken place after a jab from one of those.

I have made it a personal goal to stick my Christmas lights on them, and do.

Last night I had the normal pricks (I pre-cut the daggars off the branches) I also had two unfortunate horror moments. One as I was thinning and cutting "hooks" for lights. I clipped a branch that unfortunately turned out to be, a "Y" shape with 4 lelmons on each side and it piggybacked my arm. Then, I was trying to hook a light and the tree gave way and my hand went flying back (the equivilent of punching the trunk)

It is SOOOO painful when it happens but I started to get real achy and stiff. Then I realized it happened the night before after a knuckle jab. One of the branches cut off could be a lethal weapon. I FIRMLY believe that the tips have a "venom" of some kind.  

rogerstv wrote at 2013-01-13 13:30:45
There is some sort of poison in the thorn. A thorn punctured the skin on my hand yesterday around noon. By 4pm the joint was starting to hurt whenever I moved my fingers. By 8pm, I could not clinch my hand at all. The pain peaked with a throbbing feeling by 9pm. It is now morning and I can move most of my fingers without pain. I hope for full relief by noon today.

The puncture was maybe 1/16" of an inch in depth. It did not draw blood for the most part. No part of the thorn broke off in my skin.

I knew I was going to face pain when the puncture happened as I have experienced this before with Locust thorns.

I am not a medical expert. But, there is no way infection sets in within hours and is relieved within 24 hours without any treatment. There is some sort of poison on those thorns.

uglydog wrote at 2013-01-29 16:10:53
I have these nasty buggers on my property and get stabbed all the time with the same problem...briefly!  I've even had a thorn point embedded without realizing and become infected, that I had to lance and remove myself.  I'm no doctor, no herbalist, no degree, no certification, and no authority on the subject for sure, and it sounds crazy, but try leaves from the lowly plantain, IMMEDIATELY.  

Pick two or three of the mid-age leaves--not the youngest, not the oldest, preferably from a shady spot so they are more full of moisture.  Crush them by rolling them up in your hand and rubbing your hands together, then applying the mashed up leaves as a poultice (if they are very dry, add a bit of water in your hands.)  I have found it works for stinging nettle and bug stings (my family has a history of anaphylactic reaction to all bees and wasps requiring an epi-pen, except me ;) and they won't try it...), mosquito bites, cuts, bruises, abrasions, blisters, and mild burns, sunburn or fire... and seems to help my husband with poison ivy and poison oak too, after he's washed and still gotten blisters (he's highly sensitive to them but forgets to watch for them...)

If you plan on trying it, get familiar with it and know where it is growing on your property, or even keep some in a flowerpot so you have it when you need it.

As for a long-term existing problem, maybe try putting a few young leaves of plantain and dandelion in a salad ;) and talk to a natural healer...

Brayden Vaughn wrote at 2013-05-04 03:41:28
Hey Mr. Blake,

How do you go about removing these trees? we have an infestation of them around our property and we'd like to remove them without getting hurt. we intend on burning them, but we need to know how to get them to the burn piles! We thought about hooking up to the fourwheeler and dragging them, but dont want thorns all over the yard.. please let me know! ALSO, good to know there is no toxicity in a honeylocust, cause burning them would be a bad day otherwise..  

Ramrom82 wrote at 2013-05-12 03:16:44
I am commenting on here now because during a cleanup project today I once again fell victim to one of these nasty thorns.  It is my firm belief, after 15 years of cutting trees, that the thorns of honey locust trees have a toxin, or poison, on them.  I heal very quickly from cuts/scrapes and have had both of my fore arms covered with scratches from roses, hedge trees, and even barbed wire, with no infection, or pain.  But, within minutes of being jabbed, or even lightly pricked by a honey locust thorn I experience intense localized pain, swelling and hardness around the entry wound.  There is no way such instant and intense reactions could be caused by infection as many "experts" suggest.  I know that many such puncture wounds can become infected if not properly cared for. But the first symptoms that I, and so many others, have experienced is the bodies response to a substance that is much more toxic then mere dirt, or foreign particles introduced under the skin.  With light pricks on my arms the localized pain/swelling lasts for a few hours.  In the case a deep puncture, as I experience in my right calf today, the pain lasts for several days and makes the effected part of the body almost immobile.  I also noticed today that the pain spread from the entry point and then upward at a rapid pace to about four inches about the entry point - I could actually feel the tissue in my calf responding as the blood carried the toxin upward from the entry point.  This confirmed for me my long held belief that there is a substance on honey locust throns that is toxic to humans.  

I hope this is helpful.

Rhonda Sue Davis wrote at 2013-06-06 07:06:46
I have been tackling a weedy stump sprout area of Black Locust Tree remains this past year and same thing, get poked and later it swells up and takes several weeks to work out the effects.

Finally had to research the thorn wrote at 2013-07-01 05:36:52
I have been helping a friend with his lawn care business for 30 years and have spent countless hours trimming low tree branches and picking up fallen ones. We both have been spiked by locust thorns quite a few times over the years and both experience the same symptoms. Within an hour the spot where poked gets red and swollen like a bee sting and seem to get temporary arthritis for several days in the joints near the puncture wound. Neither of us has ever had a tip break off or get a "sliver", but the area is as sensitive as if there was something in there. Toxic, Shmoxic... there is definitely some type of toxin, chemical or irritant on the dang things.

InPain wrote at 2013-07-12 05:13:45
Same experience here. Got pricked in the palm of my hand at the base of my ring finger around 7pm its 12am and my palm and finger are in pain, its hard to move the finger, it feels as if the nerves or joints were injured kind of like a sprain ankle, very weird. Form the link posted previously some of the symptoms described are: CLASS OF SIGNS: Depression, poor appetite, weakness, paralysis, abdominal pain, diarrhea (which may be bloody) and abnormalities in the heart rate and/or rhythm. Death is possible - See more at:

lm wrote at 2013-10-29 20:17:04
I had the misfortune of having a locust log fall on top of my foot two months ago. This sent a thorn fairly deeply into the top of my foot. I'm a fairly tough Missouri farm woman, but by the next morning I couldn't walk. After a visit to urgent care and surgical removal of the tip of the thorn, I was laid out for a week- I couldn't walk. Doc prescribed antibiotics and painkillers. Now, two months later, I still have a large knot on my foot, arthritic-type ankle pain, a very limited range of ankle motion, and daily swelling of my foot and ankle. I still cannot wear any tight shoes on that foot because by the end of the day I cannot get it off. I hope it goes away, there has to be some reason why these thorns cause the body to react so strongly.  

Spence wrote at 2014-01-10 23:38:43
Many years ago I got a good jab in the knee with a honey locust thorn.  It did not get infected but it produced some very weird symptoms later.  At night for about 4 nights I would have intense pain in the knee for about 20 minutes and then it would go away until the next night.  After those symptoms subsided my knee would just give out and almost land me on the ground.  It eventually returned to normal in several weeks.  About 2 weeks ago I got poked in the lower part of my index finger and it is still swelled up with no improvement.  It is not to painful but is stiff and useless.  No doubt in my mind there is some kind of toxin on it.  I think it might be similar to the toxin on catfish spines, only fish pokes go away quite rapidly but they sure hurt initially.  I am going to try electrically shocking the finger hopefully tonight to see if that will neutralize the imaginary toxins. I heard that electricity will neutralize snake venom.  I like one persons suggestion about using plantain leaves but they are long gone from the winter temps.  

Clempson wrote at 2014-03-21 08:39:37
I was stabbed by a locust thorn yesterday in the finger through a glove.  It did not hurt right away but a few hours later resulted in disproportionate pain much like a severe sprain.  It certainly feels like a toxin and a local physician advised that he had heard of this with locust thorns.

Vicki Sinclair wrote at 2014-03-30 11:19:40
I too was recently poked by an unknown to me thorn. My pinky is now in day 4 of extreme bone and joint pain. I published my story, along with your link here to this topic. Any new info would be great!

ccspin wrote at 2014-04-18 01:50:50
I have a very odd reaction to report.  I was exposed to poison ivy 10 days ago, and was scratched up while gardening, but did not react very much to it.  No itching, no spreading rash.  Yesterday, I was pricked by a honey locust thorn on my right hand.  Within a few hours the poison ivy scratches (not even a proper rash), which were almost healed, began to itch and swell, starting with the scratches closest to the thorn prick.  Its now affected all my previously un-inflamed ivy scratches...the itch is pretty intense, just took Benadryl and am watching it.  There must be an allergen at work...

ccspin wrote at 2014-04-18 01:51:08
I have a very odd reaction to report.  I was exposed to poison ivy 10 days ago, and was scratched up while gardening, but did not react very much to it.  No itching, no spreading rash.  Yesterday, I was pricked by a honey locust thorn on my right hand.  Within a few hours the poison ivy scratches (not even a proper rash), which were almost healed, began to itch and swell, starting with the scratches closest to the thorn prick.  Its now affected all my previously un-inflamed ivy scratches...the itch is pretty intense, just took Benadryl and am watching it.  There must be an allergen at work...

Daniel wrote at 2014-05-18 19:02:07
Sorry for my English first. We have this tree in Romania from 1852, acclimated for its many benefits, as wood, soil stabilizer, honey etc. The doctors share the opinion that the thorns could be poisonous, creating inflammation, pain, in some cases nausea, fever and thrills. At the emergency rooms they gave antibiotics, anti inflammatory and anti allergic. The people in the country side use the lowly plantain leaves and the cabbage leave to heal the swollen and the inflammation...

jake but the wood splits nice and burns hot wrote at 2014-05-19 18:19:33
to brayden vaughn,

right now my right knee is really swollen and sore from a poke from a locust tree on 5/15/14. i got stabbed about 45 seconds after i burned the thorns off a tree still standing. just light a fire at the base of the tree and it will flame up as far as they will reach the the next clump of thorns. if you have doubts just take a propane torch to the thorns. they crackle and pop and turn to powder.the way they burn seems like there is something on them. could this be the substance that causes the pain and swelling.

Heidi C wrote at 2014-06-11 16:09:48
Wow, I had no idea the black locust tree in our front yard was so dangerous.  Three days ago I was pruning it and got stuck in my middle finger knuckle from a thorn.  It is now red and swollen, and I cannot move my finger.  It would be great if someone would do some research on this apparent toxin, as we live in California and bought this tree from a nursery!

D. Sjoberg wrote at 2014-06-23 17:21:50
On May 3rd, 2014, I limbed the lower branches of a black Locust tree which was planted on my property by a previous owner.  I received a deep muscle puncture just above my right knee by one of the spines as a 4" Dia. branch fell.  I pulled the thorn out (about an inch)and the tip of it was missing (either left inside my leg, or was missing before I was punctured).  I kept working because I'm one of those "driven" weekend warriors.  I had to stop working within the first hour due to pain and swelling.  The swelling radiated down to my right foot which swelled to the point my shoe would not fit.  I used crutches to get to the doctor's clinic.  Now, it is June 23rd, 2014.  I have been out of work for a few weeks now, unable to do my job.  Medical bills are starting to get scary.  Two clinic visits; one ultrasound; two emergency room visits; two courses of antibiotics (one deep muscle and one for skin issues), and I am still struggling with extreme joint pain. The swelling in my ankle and foot have gone, but there is still water on the knee.  During the first emergency room visit, knee(Synovial)fluid was drawn and tested.  It was just below the 50,000 count, and 4 days later a different bacterial culture grew in the specimen sample, which resulted in the ER doc ordering me back into the hospital for a second emergency room visit on Father's Day.  I met with a surgeon and will be seeing him again this afternoon.  If you have one of these trees, STAY AWAY from it.  I used to have a high pain tolerance, having had dental and root canal work done without numbing medications.  I dislike narcotics and am taking 50 mg Tramadol tabs instead, which offer some relief and I would recommend so you can do daily chores without being "loopy." I also soak the leg in the hottest water with epsom salts, which I can stand.  This has helped, but you need to see your doc and get his approval before doing this. After going to the store or standing or walking, I have found that icing the knee helps as well, 20 minutes on, 20 minutes off, 20 minutes on, all while elevating the knee.  Two days ago in the grocery store, my knee gave out and I nearly fell down, quite by surprise. This has NEVER happened before. I still don't know what happened there. Before this, I was a very active 58 year old male. Now, I feel just beaten by this tree thorn.  I am grateful to those of you who have posted here, and I hope my posting will serve to help someone else.  I love gardening and motorcycling, jogging, you name it, but right now, all I want to do is elevate and ice this thing and to find out what the surgeon wants to do this afternoon.  For what it's worth, I think these are dangerous, poisonous thorns.

Laurie wrote at 2014-08-02 04:42:49
D Sjoberg, I would love to know what your surgeon said. I was stuck in the foot at the end of April. I, too, feel best when I just elevate my foot and stay off of it.  I have redness, swelling, two hard lumps in my foot.  I'm pretty sure there is no thorn in the foot.  Pain is sometimes severe and sometimes still just a dull ache.  I have seen my nurse practitioner, taken antiobiotics and seen a foot doctor, had 2 Xrays, podiatrist wants to do MRI, but I don't see much point. I would love to know the answer/cure to these thorn injuries.  

Smallwasp wrote at 2014-08-25 15:15:52
I just pulled an inch-deep fairly fresh honeylocust thorn from my foot yesterday with no other problems, but in the past when I've been pricked with thorns on the tree I've noticed that the pain from getting pricked was a lot more than it should be, but nothing to the effects that other people are describing. I think if the plant has some kind of toxin, it might vary in strength from locale to locale, or possible the conditions that the plant grows in could alter its toxicity levels like some other plants. If this is true it could explain why there isn't any scientific literature on this, if a botanist in a non-toxic locale did a study that says there's no toxins on the thorns, then others could possibly have taken his word for it and not bothered doing other studies.

Sarah wrote at 2014-08-25 22:20:32
I have been stuck twice by honey locust thorns. The first time as a child I was stuck in the forearm while walking through the woods. The most recent event was by stepping on one in our yard at the edge of a small woods. The stabs were painful and tender for a few days but never required pain medicine, doctors visits or any other special measures. Not fun but not nearly so dramatic!

D.Sjoberg wrote at 2014-09-05 19:56:56
Closure on my previously noted medical treatment as a result of the thorn puncture:  Yes, this does sound like quite a drama, but it is what it is.  On June 23rd, I learned the secondary bacteria was a result of hospital lab cross-contamination and not related to the thorn injury.  The surgeon drew off more synovial fluid and I attended physical therapy for several weeks to build up my leg muscles and coordination to "pre-thorn" levels.  I returned to work, and, on August 5th, a baker's cyst, which had formed behind my knee, burst and leaked down into my ankle.  My surgeon said the baker's cyst was a direct result of the thorn injury to the knee area.  Apparently these cysts form from an over-abundance of synovial fluid into the bursa, which forms a balloon of the fluid behind the knee.  The fluid is very painful when it leaks into the calf and causes immobility and swelling all the way down to the foot.  I was ordered to stay off the leg and again ice, compress, elevate, and rest it.  Then I went to the hospital for a procedure to remove the remaining fluid from the cyst, and close it.  I returned to my regular surgeon for a follow-up visit and he AGAIN drew off fluid and injected a "fair amount" (his words) of cortisone into the affected area.  He said the cortisone is a strong anti-inflammatory, and it has worked wonders for me.  I continue with the physical therapy exercises and am again rebuilding my leg muscles.  I am, I believe, finally getting back to my old lifestyle (in early September).  It cost me several thousand dollars and a complete summer.  I HIGHLY recommend staying away from Black Locust tree thorns.  My Black Locust HAS definitely been dangerous to my health.

Brandon wrote at 2015-03-23 12:52:14
I have been working on clearing a tree line with honey locust and have been poked many times by the thrones.  It doesn't take much of a jab to make the area start hurting. The worst one I have had was between the knuckles and that took nearly two years for the sweeping and pain to go away. I hate to think about later in life what my joints will feel like around the thorn poked areas. I'm not looking toward to those days.  

Ocoeequeen wrote at 2015-03-24 01:50:18
Today is Monday, I was severely pricked by a honey locust thorn on Friday. The spine landed in my blood vessel on my hand. Within minutes it swelled and within an hour I could not move my wrist without excruciating pain. I thought for sure I would be going to the doctor. I waited till Saturday and there was no improvement. I do not have health insurance so I was procrastinating as long as could. Saturday night I decided to try something. I cut a sliver of fresh garlic from the clove and rubbed the garlic all over the swelled red circle that was on my hand. Within minutes the swelling subsided and I left the sliver on the puncture wound over night. Sunday morning I retained movement in my hand and wrist and now Monday my hand is completely normal. Thought this might help!  

Ocoeequeen wrote at 2015-03-24 01:50:28
Today is Monday, I was severely pricked by a honey locust thorn on Friday. The spine landed in my blood vessel on my hand. Within minutes it swelled and within an hour I could not move my wrist without excruciating pain. I thought for sure I would be going to the doctor. I waited till Saturday and there was no improvement. I do not have health insurance so I was procrastinating as long as could. Saturday night I decided to try something. I cut a sliver of fresh garlic from the clove and rubbed the garlic all over the swelled red circle that was on my hand. Within minutes the swelling subsided and I left the sliver on the puncture wound over night. Sunday morning I retained movement in my hand and wrist and now Monday my hand is completely normal. Thought this might help!  

ken stone wrote at 2015-05-23 18:30:00
Today is Saturday May 23 2015. I was cleaning up a neighbors back yard and getting rid of a honey locust tree branch in her yard, when I felt a sharp pain on the top part of my lower right arm.Come to find out I had stabbed myself with one of the thorns on the end of the branch off the tree. IT WENT DEEP!!!! feeling a lot of muscle pain in my lower arm. cleaned the puncture immediately after it happened with a surgical cleansing scrub. hope this all works....not liking what I have seen on here with just a poke. This thorn easily went in my arm an inch. the thorn did not break off, just concerned about the wound and toxins. always heard honey locust were nothing to worry about unless any of the thorn broke off in the skin. hope all goes well.  

sm wrote at 2015-06-15 01:09:39
In 2014, I was pruning and a black locust branch that snapped back into the shin, I believe hitting the bone. The following Monday I went to doc ,they said it would work it's way out. A week later, it was weeping hurt red and swollen I went to er and they lanced it put me on the hospital for two nights. Well, finally, I pulled on the wound and a one half inch thorn came out. The wound did not heal, I was told I was a "mystery" and sent to a surgeon. After many biopsies, nothing was found. A year later that whole part of my shin is discolored, has pigmentation loss and many sores. I use comfrey ointment that seems to help. I believe my immune system was compromised and am starting to get strength back. They have become an invasive species in wa state and need to be eradicated.

Lisa Cyrulik wrote at 2015-08-02 18:13:31
I agree with Gary that there is some kind of toxicity to the plant/thorns.  I was "stuck" just this morning and no, the thorn was not imbedded.  I was clearing a tree, was stuck just below the first knuckle on my pointer finger of my left hand, and then put on a glove and proceeded.  I am now, a few hours later, in a fair amount of pain, have swelling from the joint through the pad of the finger, and a very limited range of motion due to both.  This is NOT like a thorn prick from a rose or any other plant I have encountered to date.  I have never even had a splinter react like this jab has.  There must be something to Gary's thinking even if it hasn't been recorded to date.  Perhaps it's like an allergy... only a certain population is impacted in such a manner?

Nursie wrote at 2015-08-03 16:13:57
I'be had the same, sever reaction to locust thorns, but have reversed the pain and swelling with very hot soaks. This is something I do for any painful swelling - works great for infections, if you can get heat to the infected area (hot washcloth to a skin infection, soak a hand or foot.  Has to be quite hot and almost continuous for the first evening - should be much improved by morning.

I believe this works on bites and toxic thorns by de studying the toxin. Little known fact, as no one is able to profit on it.  

Nursie wrote at 2015-08-03 16:16:20
I've had the same, severe reaction to locust thorns, but have reversed the pain and swelling with very hot soaks. This is something I do for any painful swelling - works great for infections, if you can get heat to the infected area (hot washcloth to a skin infection, soak a hand or foot.  Has to be quite hot and almost continuous for the first evening). Should be much improved by morning.

I believe this works on bites and toxic thorns by denaturing the toxin. Little known fact, as no one is able to profit on it.  

Me maw wrote at 2015-10-05 22:57:32
I got stuck my a large thorn on a Honey Locus tree this week. Did not even know until I looked down and saw a large amount of blood coming out of my arm. After a stopped the bleeding it turned black but only had a small amount of pain. Don't know if the bleeding got rid of any poison. But have not experienced any pain as of it.

Barry wrote at 2015-10-12 02:20:43
Living in Missouri and Kansas I have dealt with black locust and honey locust trees while cleaning fence rows. I am currently felling 50 or so on my new farm. Every time I get a puncture from these thorns near a joint I have pain and swelling within a few hours. It sometimes lasts for weeks. I was told by an old friend probably 40 years ago that the tips of the thorns exude a weak strycnine substance that causes the inflammation. I don't know whether that's correct or not but I do know I can count on swollen joints most every time I deal with these trees.

As for the question above on how to handle getting rid of them safely, bulldoze them and burn them where they fall. You don't want to move them much as the thorn clusters break off and livestock stepping on them will experience subsolar abscesses that are a bugger to heal.

Steve Burton wrote at 2016-02-04 15:41:58
Like "Gary Blake", I also am a farmer. I'm in north-eastern Oklahoma, and I use the Honey Locust for firewood, after the older dead trees fall and have aged significantly. I've observed that pricking (or impaling) myself with the thorns from living trees causes intense swelling and pain to the affected area, and as Mr. Blake stated, these symptoms become most intense at about 1 to 2 hours post injury. Furthermore, my experiences have shown that the thorns of dead trees tend not to cause swelling and pain as significant as the living plants. Additionally, there are a number of other thorny plants here, and I get impaled by those on a regular basis with no dilitorious effects. At present, my left, lower leg, several inches below my knee and in a muscular area is swollen, sore, and almost crippled, and my left hand in swollen nearly twice the size of my right hand, both the result of living plant thorn pricks I received 4 days ago. Neither prick was particularly remarkable at the time, and I went on about my work without thinking much about it. 2 hours later, however, WHAMMO! Swelling, redness, and significant pain appeared in and around both wound sites. I took 50 mg of Benedryl and 150 mg of Zantac (Beta 1 and Beta 2 blockers) and significant NSAIDs.  The NSAIDs helped with swelling, but the beta blockers did nothing. I CONTEND THERE IS SOME HERETOFORE UNDISCOVERED TOXINS IN THE THORNS OF THE HONEY LOCUST TREE!  Now...What is it, and what good would it do to know what it is? I dunno. Ha! Just don't get stuck by these suckers! :)

Connie D'Angelo wrote at 2016-04-08 16:25:53
I stepped on a thorn from a locust or missouri hawthorn tree 9/2015.   Immediate pain unlike just stepping on anything.  a few days later a wierd swelling in foot pad by toes on ieft foot.  Im a type 1 diabetic so i cleaned and put antibiotic cream - no blood.   a few days later the right foot pad did same thing and I have never felt same.  I had swelling in hands and joints and a muscle on right leg.  I had total weakness in shoulders and arms progessively worse.  Upon my investigations on this thorn finally last week and being told I had RA which i did not agree with and declined Methotrexate, i have learned that people with weakened immune systems such as Type I diabetic... i believe i got a fungus Candida Albicans and i have began treating this myself with proabiotics and supplements, milk thistle, evening primrose, all vitamins (especially c and d) and yesterday started taking baking soda 1/2 teaspoon with water empty stomach 2 times a day and i did finally get pain pills last week.  I have read do not take antibiotics which i did not because it could cause fungus to get worse and even permanent damage.  I do not have a tetnus shot also, and am waitng till I can clear this to do that as it says dont get one if you are ill.  My candida blood test should be back any day, but I believe this this thorn did it all.  After reading all this, many people are being treated for fibermyalgia and RA etc without ever getting tested for fungus first or take antibiotics as first choice.   My symptoms have changed from week to week but now my finger joints are cleared and i almost feel it moving out of my body each day since i have added supplements.  Magnesium chloride for baths, probiotics, etc...  get tested for the candidas albicans...i have seen 3 doctors and 21 blood tests and no doctor told me this, I researched and found all this and thank heavens i did not agree to the methotrexate or antibiotics at this point  


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Jim Hyland


I am an expert in Forestry, Forest Entomology, Forest Pest Control, and Forest Health. Extensive knowledge in Identification of insects and diseases of trees. Expert on Bark beetles and other insects that attack forests. Also a Registrated Forester with extensive knowledge in the management and care of forests.


34 years as State Pest Management Chief in a Southern state. Extensive knowledge in Forestry.

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