Bit puzzled by something that happened last night & last week as well and I'm not sure if it was an allergic reaction. Last week part of my lower lip swell up and went down eventually by itself. It was fairly noticeable as my colleague commented on it and felt like I'd had an injection at the dentist.
Yesterday evening two separate parts of my lower lip swelled up and felt very strange almost like I'd split my lip but I hadn't. I took some piriton syrup which we had left over in the house from a holiday last summer and it went down.
If it was a reaction I'm not sure what too, as I'm not to my knowledge allergic to anything.