Can allergies cause sore throat and swollen nodes? When pollen is high out, my throat hursts, sneezes and swollen nodes. Subsides with benadryl (diphenhydramine).

Sounds like. An allergic response usually does not involved lymph node enlargement but one can see how this can happen from the immune stimulation related to high pollen exposure. If the problem is relieved by Benadryl, (diphenhydramine) then what walks, sounds, and looks a duck = a duck. Yes you do have allergy and the sore throat is from either mouth-breathing or post-nasal drips.