Antihistamines

I posted recently under the title "Two Questions."  I write again, because, well, while working in a rual area this week, I was stung by a wasp.  It's been two months since the last sting.  It was a freak thing too, the way it happened.  I ask for your knowledge again to shed some light on this so I can better understand and be aware of a possible problem.  My first question is, can a daily dose of antihistamine curb or prevent a severe anaphylactic reaction?  Is it possible to have a mild anaphylactic reaction, if so what are the symptoms? I'm not that familiar with anaphylaxis so I would appreciate some information.  

Within 10-20 minutes (I think) of being stung, my nose started running, my chest felt a somewhat tight, started coughing pretty hard, was a little wheezy, and spitting up some phlegm.  My forearm, where I got stung, turned red, swelled a bit and was quite itchy.  The running nose and cough lasted for maybe an hour or so and then settled down.  I was working pretty intensly so I wasn't really paying to much attention to everything.  My partner and I just wanted to get the job done and go home.  The last two days though, my allergies have been a little bad.  Lots of sneezing, runny nose, watery eyes.

Currently my arm is still hot, itchy, mildly swollen, and slightly red.  I think the antihistamine I take everyday is helping.  If this is anything like the last sting though, it's going to take a week for it to go away.  I was kind of planning on making an appointment with an allergist, but do you think it's necessary?  Is this something I should be overly concerned about? Or am I making a mountain out of a mole hill after the fact?  Any advice you could provide, again, would be greatly appreciated.  Thank you.

[National Jewish Health]

This could be a mild anaphylactic reaction to the wasp sting.  Antihistamines may have tampered it some, but these medicines definitely cannot prevent a severe reaction.

Because of the chest tightness, I would recommend seeing an allergist to be tested and be sure.