In general, the allergy symbolizes rejection of a situation. If dreamed you that you had an allergic reaction to something non-material (for example, on communication with any person or on any book or transfer, and so forth), then in reality you should be more reserved in expression of the relation to activity of other people.
Be sure and keep any other thoughts out of your mind before drifting to sleep as a cluttered mind can decrease the chances that you will remember your dreams upon waking. Also, focusing on remembering your dreams upon waking in the morning is another very important thing. This sounds very easy, but is often hard for some to do. Interpret a dream by "dictionary dream of interpretation"
When you very first wake up, simply think about your dreams. Don't allow your mind to drift off to other things, just lay there and think about the things you dreamt about the night before - dictionary dream meaning.