About 5 days ago very itchy bumps started appearing around my mouth, jaw line and neck. Now the jaw area on my left side is swollen, red, and hot. I assume this is some sort of allergy but have no idea what from. I ve never experienced these symptoms before. I m a 44yo male. We do a lot of hiking so maybe some sort of reaction to plant or insect. Benadryl seems to help the itch a bit but has no affect on the swelling. Rashy bumps seem to appear, heal, and reappear in a new spot, but only around my neck and jaw line. No problems are evident inside my mouth. Any ideas?