Allergic Allergy
This may be showing you an actual allergy you have. Or it might be used symbolically. In this case you need to consider what the allergy in the dream depicts. Look it up in the dictionary if possible.
Useful Questions and Hints:
What event, food or other substance might I be having trouble coping with?
Is there something I have a strong feeling reaction to that I need to be aware of – aware that is of how my strong feelings affect me?
If the dream involves people am I not seeing what a bad reaction I have to someone?
You might find it helpful to use Talking As and Processing Dreams