Thank you Doc for the very informative reply! Nothing more to add except a side note perhaps: having been here over 10 yrs now and being highly allergic to these jellies, sea lice, etc. I've not found a protectant that works for me. However I did find a very effective cream to apply that is highly effective and has worked for everyone I've recommended it to as well.
Here on the island the pharmacy carries a tube called DERMATORVATE and if applied as the red welts pop up [within hrs of diving] the cream removes the reddness, swelling and itchiness immediately.
I owe this discovery to my dad really...he was here one year during May just as I had been hit hard due to multiple days of class instruction and he felt sorry for me! As coincidence would have it, he was struck the week before by poison oak and his doctor had given him this cream. We both concurred that it wouldn't hurt to give it a try on my red, swollen neck and face. The next morning not one bite was visible and no discomfort! We ran to the pharmacy and compared ingredients on the tube so I don't know what the US equivalent is but it was a prescription cream.
DERMATORVATE is readily available OTC here in Cozumel ~ in case any of you get "hit"!! I never travel without it now!!
