My boyfriend was bitten or stung by a pink coral ( that's what he saw) 2 weeks ago during their diving activity. The area (in the legs) that was stung/bitten by coral is still very itchy. It grows like a mosquito bite, but super itchy. He tried putting it white vinegar but still no effect. I asked him to buy benadryl today. What do you think I should advise him?

This wound is old enough he needs to see a doctor.

Flushings with vinegar and triple antibiotic oinment hould have this cleared by now. If it is worsening there may be microscopic foreign bodies present or a chronic allergic reaction to toxins.

Time to go to the doc. Might need debridement. Might need the specialization of a dermatologist... in fact, if his doc is unsure, insist on a referral.