Where did you meet him... your place? His place? A hotel?
Did you both take a really thorough shower (with no novel soaps, shampoos, etc)? Any lubes/lotions/latex/other materials that are new?
As @Rudynate said, it sounds like an allergen and, per @Cody Converse, seeing a doctor is warranted.
It might be something which manifests itself in another context in a much worse way in the future.
(Hopefully its not human seminal plasma hypersensitivity.)