When should a prick test reaction go down?

[podsquash]

Just wondering. My son had a prick test about a month ago and 36 hours later the Brazil nut site was still a huge lump on his arm. I mean massive, hard, etc. We ended up giving him antihistamines which helped but it was still visible after that. I read somewhere recently that the reaction will disappear on its own in a few hours. What are other people's experiences? thanks!

I thought they were supposed to go within half and hour or so. DS's reaction to the skin prick wasn't huge, but it certainly disappeared within an hour or so at the most.

Dds have always gone by the time we get home from the hospital. She usually only has the pen markings to show off! No in our experience its always gone very quick, like you say strawberrycornetto within half hour ish. Dds had more than I can remember podsquash and never had your ds's problem.