Over the years, I've been stung dozens of times including twice last week (back of the neck and back of arm at the same time). Other than a little pain at the time, never had a problem. Today was different. Got stung in the back of the head, and within 5 minutes, the palms of my hands were itching like crazy and itching finally spread to my groin and feet. Popped about a half dozen Benedryl tablets before any relief. Itching is finally gone, but after 3 hrs, head still hurts like hell. Kinda scary since palms itched worse than any poison ivy I've ever had.