I'm afraid it does sound like some sort of allergic reaction. Things that people are most likely to react to are: seeds, nuts, peanuts, sesame, soya, cows milk, eggs, fish, shellfish, citrus fruits, tomatoes.
You can react to anything though and you would already know if he had allergies to most of those (although new ones can develop). Maybe a seed/ different type of nut?
Most people react on the second time of eating something (not the first- usually fine)
Does he have any history of allergies including asthma or eczema or hayfever. Other members of the family having any of these also predisposes someone to have an allergy.
Did your ds have any other symptoms of allergy- a rash, hives, shortness of breath?
I would make an appointment with your GP as nottirednow suggested. But be prepared to fight for a referal to an allergy specialist.
Hope that helps and I hopes its something else altogether.
A couple of years ago my dh and I both had a terrible tongue problem - like geographic tongue with no other major symptoms so it could well be a virus or something else especially if he hasn't been atopic before.
I have piriton in the cupboard so I will make him take some of that to work and see if that makes a difference - I guess that would rule out anything else out - it would more than likely point to an allergic reaction
Yes, completely out of the blue. I have a relative who became very allergic to shellfish at 50, even when she had never had any problem with them before then. My friend can not eat fish since she was 38.
They can come, go with time, re appear with time and disappear again.
Wondering about sesame again, did the burger bread had sesame on it? (We had a scare with DS in Burger King, we asked for something sesame free but as most BK bread has sesame I suppose it was, perhaps, contaminated with it so...all went into allergy reaction mode. :-(