Get the testing done so you know what you're dealing with an can either mitigate the allergens (if they're environmental) or properly treat her during her allergy "seasons" if they're more typical outdoor allergies. A pediatric allergist should have a scratch kit that tests up to 32 allergens at once. At our allergist, they have 4 paddles with 8 point on each and each point has a different allergen. They then have two nurses come in and you hold your child in your lap facing you and pull her shirt up, they press the paddles gently into her back at the same time for a second and then you wait to see which spots react. It was really quite easy and fast and very informative when my oldest was tested 10 years ago. Knowing precisely what he is allergic to and when those allergens are in season turned months and months of illness into a predictable, manageable season that we can prepare for and treat effectively.
For the time being, try just benadryl and see if that reduces her irritation and dries her up. It may just be that she has a lingering cold or series of colds. Around where I live, there is a virus going around that lasts 4-6 weeks and it's hell on the sinuses.
Also, try to avoid using antibiotics on the ear infections if at all possible. If they're caused by a virus, many will clear on their own. I learned after my 2nd son (the king of rebound ear infections...8 infections in 6 months) to not even go to the pedi until day 4 or 5 and just try to treat the pain with ear drops and tylenol/advil. Obviously run this by your doc first but see if he or she will agree to a more conservative approach to treating the next one. It may be what you need to break the cycle and get her immune system fighting on its own.
Speaking of which...make sure you are giving her a probiotic to counter the antibiotics as well as extra vitaman C, echinachea, and zinc to boost her depleted immune system. My mom has recently been all the rage about grapefruit seed extract so you might want to google that and see if it looks like it would help.