Sea Urchin Sting (Wana)

Every practice setting has its specialty. For Poipu Mobile MD it appears to be “Wana” stings. Patients often arrive after surfing, or walking on shallow rocks. They generally describe a sudden stabbing pain, which ramps up far beyond what you may feel by stepping on a nail. Puncture by the spines causes one level of agony. But it’s the venom from the spines and “pedicellaria” in between that crank the pain up to 11.

Patients call regularly with this problem. The most recent victim to call said it was the worst pain he’d ever experienced, and far worse than when he broke both bones in his lower leg. He said it was like a wave that took over his whole body, then he couldn’t think straight and nearly passed out. (Naturally, all the mothers in the room rolled their eyes.)

The quick fix in this case was a bupivacaine digital block. That bought time for conversation and a little digging.

Red Flags:

• Weakness
• Breathing problems
• Lost consciousness
• Fevers
• Pus
• Red streaks
• Protruding spines
• Suspected joint involvement
• Frail, elderly, kids, diabetics

Happy Words

• “I got the spines out, and the pain’s gone. I just wanna be sure it’s ok.”
• “It happened a couple days ago, but the black marks are still there.”
• “Sure, I can take a few days off work to elevate my foot without walking. Can I have a work note?”
• “The pain got better when I peed on it.”

While horrible in appearance, most of these stings resolve with time and TLC. Soaking in vinegar can help to dissolve the calcium carbonate spines, while warm (approaching hot) water can help to neutralize the toxins as well.
My approach is initially focused on killing the pain. Local anesthetic generally does the trick. Then I aim for the low hanging fruit. Any spines that are still sticking out I’ll try to remove to limit additional penetration into deeper tissues. Lastly, I’ll trim calluses to help remove whatever possible without turning the affected limb into hamburger.

Bacitracin and a loose dressing along with crutches are a nice touch too. I’ve never heard of anyone getting tetanus this way, but we still make sure patients have had their vaccinations. Oral antibiotics are considered as well, especially if we suspect joint penetration. But generally not needed. Soaking, NSAIDS with food, and Netflix binging with feet up are probably the most important steps.

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