Lionfish stings – first aid and treatment

It is said by those who know personally, that it really is not very nice at all to be stung by a lionfish. I have seen a number of my colleagues get stung and they were in agony. Their faces were contorted in pain.

Lionfish sting first aid and treatment

The lionfish venom itself is contained in glandular tissues that are located in the grooves of the spines. As the spine enters a victim the sheaf is pushed back which allows the venom in the grooves to penetrate the wound.

Since catching my first lionfish in 2009 I have been stung 5 times, once with nets, once with a spear and three times while cutting them up. I suppose that is not too bad, 5 stings versus over 10,000 kills. However, all of those stings were a really big shock to me at the time they happened. I never thought I would get stung once, let alone five times. All five hits drew blood but the pain I felt was never bad. Is that because every time I do something immediately after a sting that I have NEVER heard anyone else mention. When I first got stung it was an automatic reaction.

Can you think what I did? I will let you know at the end of this post.

Why does a lionfish sting hurt?

How much a sting (envenomation) hurts actually depends upon a number of factors, which include how many spines penetrated the skin, how deep those spines penetrated, the size of the lionfish, the actual amount of venom injected, where on the body the person was stung and the strength of the immune system of the patient. Perhaps I have an amazing immune system, although I don’t believe I do. However, I believe it is what I automatically do immediately after I get stung that helps me and which can hopefully help you.

Lionfish stings - first aid and treatment

What are the most common symptoms of being stung by a lionfish?

The main symptom is initially a sharp pain and then an intense throbbing that goes on and on and on. That throbbing can then spread from the initial area that was stung. Other common symptoms include a tingling sensation, sweating and blistering. Signs that others will see besides you sweating are that blood may be coming out of the wound and over time the area that was stung will swell up. The good news is that no deaths have been reported from any lionfish stings in the western Atlantic or Caribbean. However, some divers have experienced a severe allergic reaction.

One such diver where we live in Grand Cayman was one of those unlucky individuals when he was stung less than a year after we saw our first lionfish here. Here is a link to the Cayman Compass newspaper article dated 8 June 2010, outlining the serious effects of necrosis.  This guy lost much of the skin off his finger, and it was reported at the time, he was lucky that it wasn’t even worse.


Photo courtesy of the Cayman Compass at

Please note that while writing this post I have assumed that the patient (person stung) was stung on the hand, which is the only area of the body I have ever seen anyone stung. As mentioned I have been stung five times and I have otherwise witnessed approximately eight stings of which two were excruciatingly painful.

First reactions to being stung

Remember if you are stung while diving you should try to remain CALM – which sometimes in life is far easier to say than do. You should then let your buddy and dive leader know that you have been stung – although I am not quite sure what the international underwater signal for “Ow I’ve just been stung” is. However, you must SAFELY ascend without delay, with a normal ascent rate, and don’t forget to complete any necessary decompression stop, albeit I have never gone into “deco” on a hunt and strongly recommend that you don’t either. You need to start first aid treatment as soon as possible. Remember if you do decide to continue the dive there is a much greater risk that a severe reaction may occur, and you don’t want that to happen while underwater.

Initial lionfish sting first aid and treatment

Lionfish venom includes a protein, a neuromuscular toxin and a neurotransmitter called acetylcholine. As the venom is protein based then heat will break down the protein and thereby the pain will be relieved.  That’s why the immediate first aid is to immerse the affected area into hot water – it reduces the pain.

Lionfish stings - first aid and treatment

When you are on a lionfish hunting dive you should always remember to bring with you a thermos of hot water, or better still bring two. You should also have a high sided container available to mix some sea-water with some thermos hot water. The container we now always have on the boat is a one gallon bottle with a hand size hole cut in the top side and with the handle retained. We used to use a mask box but we found if we were returning in wavy seas most of the water would slosh out after the first few waves. The high sided bottle retained most of the water even in big 6ft seas.

These bottles also worked very well when it was the Captain of the boat that got stung and he had to drive the boat back to the dock in heavy seas for over 30 minutes.  One-handed, because the stung hand was in the hot water container.  Not much fun.

Remember to put the cooler water in the container first and then keep adding thermos hot water a bit at a time. The heated water should NOT exceed 113 F (45 C) albeit that assumes you have a thermometer readily available. Remember that numbness may be a symptom of the sting, so to avoid a scald, then the helper should try the water on themselves first. If the helper can tolerate more heat then they should take their hand out of the container, add more thermos hot water, and then carefully put their hand back in. Once the helper has found the hottest water they can tolerate then the patient can now put their hand in, and not before. The patient should then get instant relief.

However, after some time the water will gradually decrease in temperature and the patient will notice an increase in pain. Now ask them to remove their hand, so that you can safely add some more hot thermos water. Repeat as necessary or until all the hot water runs out.

DO NOT add hot thermos water to the container while the patient’s hand is still in the container. I witnessed the after effects of this once on our dock when one of my colleagues unfortunately made this mistake on the boat on the way back to the dock. His friend had a very nasty scald which he said hurt a lot more than the original sting and took a long time to heal.

Lionfish sting First Aid and treatment summary

  1. Remove any obvious spine(s) protruding from the wound, using a pair of tweezers if available.
  2. Rinse the wound with clean fresh water. That way you will get a better view of the wound especially if it is bleeding.
  3. Now you must apply some heat. This is the stage of the treatment that will give the injured person the most relief. If you are able, you should immerse the affected area in hot water for between 30 minutes and 90 minutes, or until there is little or no pain when the affected area is removed from the water.
  4. Monitor circulation, airway and breathing.
  5. Go and see a doctor as soon as you possibly can. Ideally, someone who has dealt with a lionfish sting before.

No hot water?  What then?

If you forgot to bring your thermos of hot water where else can you get some hot water? If you are on a boat then the exhaust water is hot enough to provide relief. Also you may like to lay a wet piece of clothing or towel over the hot engine block and then wrap this around the sting area. The relief should be temporary but at least there should be some relief.

Reusable heat packs may also provide some relief for a short period of time. Heat packs should be an essential kit item for anyone who plans to catch lionfish.  Trust me, when and if the time comes, you’ll be more than delighted that you invested in a couple of these to use when no hot water is available.  These are my favorites, and they get good reviews. Medical grade and all made in the USA.  Get them!

91UUhXoCCkL._SL1500_HEAT WAVE Instant Reusable Heat Pack – LARGE (8 x 12 inches)

  • Instant heat and reusable – HEAT WAVE BRAND – made in USA
  • Large pack heats up in under 60 seconds
  • Lasts several hours under clothing or fabric
  • Reusable 500 times and more – Premium Quality – Medical Grade
  • Eco-Friendly – reusable – never has to be disposed
41XHMEAr4FLHEAT WAVE Instant Reusable Heat Pack HAND WARMERS – 4 pack = 2 pairs
Same features as above, but smaller. Double pack of 2 small ones, making 4 packs in total. Use one, then when it cools, activate the next and so on, for longer relief when you are further from help.
91vllOxQj+L._SX522_HEAT WAVE Instant Reusable Heat Pack – HAND WARMERS (2) = 1 PAIR
The bare essentials you should have in your kit.

If you are on the land then you should ask some person or business locally to heat some water for you. Remember that peeing on the wound is useless as your pee is at body temperature.

Lionfish sting first aid and treatment

Which are more ‘dangerous’?  The big or small fish?

When it comes to the size of a lionfish you are much more likely to receive a painful sting from a smaller lionfish than a larger specimen. This is because the spine tip is smaller and sharper, and the venom is found closer to the tip of the spine on the smaller fish.

Plus, when you see a large fish, you may be more wary and careful perhaps because of its size and strength.  But the tiny ones can still pack a punch, so take care with every fish!

How might you be able to reduce the effects of a sting with some quick action?

So what is it that I do AUTOMATICALLY  and immediately every time I get stung? I squeeze the sting area hard between my thumb and forefinger – blood comes out and hopefully some venom, effectively flushing the wound and the venom out. Does it work? I think and I hope so. Would it have been more painful with no squeeze – who knows. I’m not going to try that experiment to see!

Now have a look at my post on lionfish spines and see how the spine injects the venom.  There are some really interesting close up pictures of the grooves in the spines and how they act like needles to inject you.  Check it out.

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About Nigel Coles

Hi my name is Nigel Coles. I used to live in Bristol, England but after a change in direction we moved overseas to work in the scuba diving industry. After a time in Thailand, for the last 8 years I have been living with my wife Deby, in the East End of Grand Cayman, The Cayman Islands. I’m a dive instructor, working for Tortuga Divers, part of the Red Sail group. I spend my day on dive boats, training students and taking our guests on dive trips. It’s a hard life but someone has to do it

3 Responses to Lionfish stings – first aid and treatment

  1. THOMAS ANHOLT says:

    Yes, I just got stung between thumb joints last week while hunting in Bonaire. I instinctively bled the wound. It was interesting watching the blood spurt out underwater. I was already in the shallows for quite a while and was low on air, so I went up. I did not have any way to heat the area, so I ran ice water on it. Used hot saltwater when I got back to shore. Not super painful just a dull ache. My big thumb joint still hurts now a week later.

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