Blood and penicillin

[kaktus]

Inspired by a question in Chatterbank... According to answers in that thread, you can give blood in the UK if you're allergic to penicillin. You can�'t do that in Denmark. So I was wondering, is the Danish rule too strict or is there an actual risk of giving blood when allergic to penicillin and thus the British rules might be lacking in this area? Obviously I mean risk for the reciever of the blood not the giver. :0) Anybody with great technical knowledge of blood donation out there??