I was stung by a large jellyfish and the pain still persists after a few hours. Help needed.

miklcctmiklcct London, United KingdomMem​ber
edited March 2021 in Beginner Questions

I swam with my newly-met friend in my home town (Tuen Mun, Hong Kong). About 45 minutes into my swim I hit a large brown jellyfish with long tentacles (more than a metre). The water was brown and murky so I couldn't avoid it and hit it with half of my body, including my lips, my right arm, under my right armpit and my right ankles, and also a bit of my left forearm. The pain was so intense so I nearly wanted to cry and my form was seriously affected. Luckily my friend was much slower than me so we could still stay together.

I could only concentrate back in my form after around an hour but the pain still persisted. I got out of the water about 1.5 hours afterwards and got home and I'm still feeling intolerable pain. I have applied white vinegar and the pain still persists till now. It's now about 3.5 hours after the sting and I still can't concentrate my mind. There are no other ill effects except intense pain and swollen skin.

Normally in this season I swim with increased coverage, but last week I found my swimsuit too small and it chafed my nipples so I returned to standard channel swimsuit today and the worst thing happened to me. The last time I was stung by such a large jellyfish was about 3-4 years ago with the same intense pain. Now I'm really scared.

A Google search using the description suggest that the jellyfish may be the dreaded Lion's Mane, and the pictures confirm the suggestion. There are also articles about Lion's Manes appearing in Hong Kong by including the government but the Wikipedia article says it only appears in cool water (which Hong Kong isn't). What species do you think I was stung by, which is large, brown, with tentacles over a metre? What should I do now to mitigate the pain?

Also I'm now really scared. I can confidently say that 2 such stings can end any channel swim for me because the pain is intolerable. How can I avoid them?



  • flystormsflystorms Memphis, TNSenior Member

    Go to the doctor?

  • KarenTKarenT Charter Member
    edited August 2020

    Occupational hazard. I had an encounter with a Portuguese Man of War last Xmas. Anti-histamines + warm water helped, but I also had a bad reaction and threw up a lot and had some problems with infection and healing. But once it’s done, you just need to get back in and try not to let it become a thing. If I’d been stung repeatedly like this during a long swim, I would not have been able to continue, But that’s how swimming goes. You obviously got a thorough stinging - give yourself time to recover then try to get back in. It’s their territory, but if you’ve not been stung before, it’s probably just bad luck that you got caught this time.

    [originally posted gruesome pics but decided no-one needs to see that. Take my word for it - it wasn’t pretty].

  • I witnessed one of the toughest women I've ever met tangle with a Man of War the day before a half-iron distance triathlon. FREAKED me the hell out, to be sure. She got up the next morning and proceeded to earn a top-10 finish time for her age group, welts and all.

  • KarenTKarenT Charter Member

    @Sara_Wolf it was excruciating and quite scary. Fortunately, I could sit around and feel sorry for myself for a few days. But good for her - the welts just add character.

  • andissandiss Senior Member

    I was stung last week by the same jellyfish- not as bad - I used some antihistamine cream - it worked well.

  • miklcctmiklcct London, United KingdomMem​ber

    I'm mostly fine now after 18 hours. There's still a bit feeling on the skin of my right arm. I visited a shop and got a new upper body swimsuit today (the old one was too small and it chafed my nipples after a few km), hope it will be comfortable.

  • WillMWillM NorwayMember

    Dousing the affected area in really hot water (please don’t burn yourself) denatures the proteins causing the pain and gives relief.
    A combination of paracetamol + ibuprofen + antihistamine also helps if you don’t have a contraindication.

  • wendyv34wendyv34 Vashon, WASenior Member

    I hit a lion's mane last month. Fortunately it was off to my left (in super murky water) and only stung my forearms/hands and shins/feet when I swam over the tentacles, so glad it wasn't my face. I was miserable for about 10 hours and struggled to stay asleep. I used vinegar in the shower and repeated scorching hot water rinses on my arms. I took Benadryl and Aleve, around 3am the stinging subsided.

    For prevention, there's a product called Safe Sea, which I've remembered to use that last few times I've gone out in the harbor. It doesn't stay on for more than a couple of hours, but when I did a 7+ hour swim, I put on a coat of long lasting zinc sun block, then Safe Sea, then another coat of sun block. I swam through a lot of moon jelly swarms, where the painful jellies tend to lurk, but I didn't feel any stings until a bit over 6 hours. It's expensive, but worth the cost to prevent or minimize stings.


    It's always a bad hair day when you work at a pool.

  • miklcctmiklcct London, United KingdomMem​ber
    edited February 2021

    It's now jellyfish season again and now they appears in large numbers in Hong Kong. A project has started for research.

    In particular, there are a large number of ghost jellyfish (cyanea nozakii), in the same genus of the dreaded lion's mane (cyanea capillata). Some even classify them as a race in the same species (cyanea capillata nozakii). They are so scary but basically unavoidable now and they are freaking me out even in all my swims, even when I'm racing. I have hit their tentacles in my swims and I'm really scared about getting stung.

    Cyanea nozakii © Ryan Yue Wah Chan (CC BY-NC 4.0)

    Does anyone here know how bad is it when compared to lion's mane (found in the North Channel)?

  • celsarbo5celsarbo5 FresnoMember

    I can certainly understand the trepidation now after it sounds like you've had multiple encounters with them. The one time i got stung bad was on my inner thigh, only an inch from my crotch. That left me pretty shaken..

Sign In or Register to comment.