Sea Urchin spikes embedded in foot

Son stood on sea urchin in Italy, painful for a while but no lasting effect.

Happened to me in Greece about 17 years ago, my husbands
removed what he could with tweezers, antibiotic cream and it was fine.

Thank you for that reassurance

Same experience in Minorca a long time ago. Boyfriend did his best with tweezers and eventually, like with a splinter, the body expels the remains.

There was a very funny episode of "Friends"' a number of years ago, anyone remember? The anti dote at the time was said to be urine. Doubt if that is a true one. I have heard of the tweezers and anti biotics.

They say urine for jelly fish stings too we sometimes get weaver fish here and they are baaaaad

Yes, I did many years ago swimming in the Balkans.
A sadistic nurse at the local hospital dug them out.

Seawater helped but afterwards the tour rep said it often happened to her as a child and putting a large dressing on with antiseptic ointment would draw it out (after they'd been dug
out painfully!).

The antidote at the time was said to be urine
Yes, urine for jellyfish stings as Bluebelle says.
Or vinegar

I did have a lot of helping hands on the yacht pulling most of them out immediately but some were more stubborn.

Urine for jellyfish stings is a definite no-no, I believe hot salt water (not fresh) is used but that is not what the OP was asking about.
Sea urchin spines should be pulled out with tweezers, finer spines can be scraped out with a knife or bank card then the foot should be soaked in warm water or vinegar which dissolves the spine.

Dear me that sounds painful. Sorry no advice to offer, but sorry for people this has happened to. Not nice.

I used tweezers when MrOops trod on a sea urchin over 40 years ago, he still remembers the pain, plenty of Germolene afterwards, he was fine.

My daughter had two very large spikes removed under local anaesthetic today. The doctor said he had never seen ones so large embedded in someone’s foot!
She is on antibiotics and painkillers but grateful she didn’t have to undergo surgery and a general anaesthetic.
Immediate expert medical attention is my advice to anyone who experiences this!
Many thanks