Ask HN: Does this web app already exist?

With the allergy season in full swing, I'm absolutely miserable, but I've realized that I'm not entirely sure what I'm allergic to. Is there a website that I can enter my email address and zip code and let it figure out what I'm allergic to? It could give me an e-mail survey at night, asking me to rate my allergies on a scale from 1 to 10 for the day. It could also ask about other symptoms, such as cough or runny nose. It could then monitor the allergy indexes for me and identify what I'm most likely allergic to.

Once it has figured this out, it could e-mail me in the morning when the allergy index is high to let me know that I would probably benefit from taking some allergy meds.

Does such a website exist? If so, I would love to use it. If not, I think it may make an interesting weekend project!

edit: fixed a grammar issue.