Sorry you are dealing with possible (environmental) allergies. We are too! My poor DD...I should start apologizing to her now for the genes she's getting from both her daddy and me.
She is 9.5 mos. old and last week during her "sick visit", her pediatrician told me that 2 out of 3 little ones this age who have allergy symptoms...after blood testing, it turns out it's not allergies. A few days ago at her 9 month checkup, her pediatrician suggested we have the blood test to see if she has allergies. I told him that thinking about putting a needle in her was bringing me right back to the NICU days!! It's not urgent that she has the test, and we're treating her the same way even if she did have allergies, so we'll do the blood test in a few months when her ped. wants an anemia test done, too.
This pediatrician is well-respected in our area and has been around a long time. He says that it takes at least 6 months of being exposed to something, usually, for a little one to have an allergic reaction to it. A blood test can determine if the allergy "mechanism" is "turned on", but won't tell what the little one is allergic to. Our ped. suggests 1/2 tsp. of Children's Claritin, once every 24 hours. The bottle starts at age 2, but our ped. who I trust says he's looked into it quite a bit and feels this dosage is appropriate and safe.
How can you guess it might be allergies? Do baby's bio mom and dad have allergies? Does baby have other allergy things (like cradle cap, ridges in her nails, like my DD)? Does baby rub eyes and nose a lot, pull on ears/clear runny/sniffly nose? Does baby scratch? (My DD has scratches on the sides of her thighs; poor thing). And she's often scratching her head. Some of this is just normal baby behavior, so it's tough to tell.
Her ped. left me with this: whether or not she has allergies, it depends on her level of comfort. If she is exhibiting behaviors that show she is super unhappy or misearble and it looks like it could be due to allergies, try the Children's Claritin and see if there is a difference. We did this test; no Claritin yesterday (she was more fussy yesterday) and Claritin today, and there definitely is a difference for us.
So for now, at least for the next month or 2, we're sticking w/the Claritin. Sorry this was so long. It's all just so fresh in my mind. I hope some of it may have helped you!
~Sandy/DD born via emergency C at 35 wks. June '03 due to Severe PE/class III HELLP/chronic HBP/asthma