I take Claritin also, but added Nasacort a year or two ago. I thought you should only use one or the other until I found out a couple of friends were taking both a systemic antihistamine and a local nasal spray. They were using different antihistamines, but the same combination of a pill and a spray. It helped me to add the nasal medication. Flonase has never worked well for me, but I seem to do well with the Nasacort.
Maybe they just get worse as you get older. I never had any until 3-4 years ago. They generally only bothered me when running but now sometimes even when just hiking. If it keeps up I'll have to look into trying something stronger than the Claritin.