Well I have had problems with the school. Mainly getting them to recognise hayfever (poss grass pollen allergy - awaiting RAST test results although I'm not holding my breath for any answers atm
). DS symptoms are the usual itchy eyes/skin, hives on face, aggitated etc. Trying to get people to recognise it as allergy not just an inconvenience has been a battle. He does have severer reactions occassionally.
Now that it has been recognised that he has allergic reactions as well as the hayfever (and prob similar if not the same allergen) and he has epi-pens they are taking it more seriously. The main problems faced are getting people on board. Not treating me as a PFB over reactive Mum but of a mum with a DS who has an allergy, who doesn't have the answers herself (and wants/ needs them).
DS has not had a reaction in school. Once last summer he was on Chlorphenamine 3x a day (am, after sch and before bed). He went to the secretary at lunch and asked for a dose. It was refused 'as there was nothing wrong with him'. By the time I collecetd him he was very flushed with some hives and eyes very red raw, black and puffy underneath. I took him to the GP who then confirmed I was correct in treating it as hayfever and prescribed him 4 doses a day so the school would give him a dose every lunchtime.
From this I would say the most important thing is to be sure you make it clear to the school what the symptoms are - that allergy isn't always necessarily a quick and serious reaction and sufferes can tell when they are reacting to something before any obvious signs and symptoms. Even now (haven't had the care plan meeting yet) all I get from the school is we're all epi-pen trained. Yes, great, very reassuring.
. But more information IMO needs to be given about the different allergic reactions and degrees of seriousness. That anaylphaltic shock is the worst case senario and if treated correctly can be avoided in some cases.
For me its all about the risk assesment. For example you know a child with food allergy is high risk during cooking sessions, lunchtime etc (although I do fully appreciate cross comtamination). DS just seems to be at risk. He could be in the class room, playground, lunch hall, library no one knows - there is nothing to avoid, no way of limiting the risk. 
Having said that though, he seems to have less reactions than an atopic child or child with food allergy. If you discount the 4 months of hayfever he only had 7 reactions in total last year. 2 minor, 4 moderate and 1 severe.
What I'll do is when I've had the care plan meeting I'll write again about what was discussed. How the school reacted, what is going to be done and anything the school nurse suggest as well.
As mentioned above the main jist of what advice I could give (and would have liked) is the difficulty is getting allergy recognised when you can't simply say 'X is allergic to x,y,z when he inhales, digests or touches it'