Yu can get allergens for things other than pollen. Have you recently bought a plug in air freshener? used a different clothes conditioner,shampoo, hairspray? the list is endless. Buy some cheap anti histamine tabs from the chemist -boots do a good on at about £1.99 take one and if the symptoms subside then its an allergy. On the downside I started with similar symptoms at the beginning of December that turned into a humdinger of a bacterial infection -still on anti-biotics but had no sense of smell or taste all Xmas.