Big scary swelling on back

[jellyrolly]

DS1 had a large swelling, size of an egg, on his lower back on the spine, seems to have come up tonight. He says it itches and it has stopped itching so much with Piriton but still looks big. Anyone have anything similar?

I had a number of Mosquito bites like that...I am allergic and sometimes react strongly. Is this possible?

Yes it could be, I just got a bit worried as it appears to be on his spine but I think coming up so quickly is probably an allergic reaction.