I wanted to respond to the person as well. My husband and I were in Hawaii and upon swimming back from Chinaman's cape, I was stung several times in the arm, hand, neck, and face regions by a wayward man of war. I can certainly empathize with the person questioning about the reoccurrence of the hive-like bumps, as a week later, I, too, had a reoccurrence. I noticed that about a week after I had gotten stung, if I exercised or sweat at all, that would bring the bumps back out. I put cortisone cream, over-the-counter, on the affected areas and tried not to scratch. It took a few days for the affected areas to calm down, but when they did, I haven't had a problem since, and it has been a month now. By the way, vinegar works great when stung, and it is very important to check the areas where you were stung, as I had stingers stuck in my elbow, and didn't realize it until the pain did not cease after putting vinegar on. My husband found them and commented that they looked like my own arm hairs.