Until they test him for seasonal allergies, you won't really know if he has them or not.

My son has lots of food allergies, so his doctors are very quick to blame allergies, even seasonal ones which he has not yet been tested for.

Last year he was sick for 8 weeks with what the doctors said were seasonal allergies. He was so sick I brought him in three times, on the third visit they finally discovered he had strep the whole time and had gotten scarlet fever.

A guideline for you though, allergies do not come with a fever. If your son has a fever he probably has a cold/virus. I know a lot of people insist that teething children get fevers, so that may not help you much with a 10 month old.

Also I am assuming that if your child has already been diagnosed with food allergies, you know what dosage of Benadryl to give him in the event he is exposed to one of those foods. Ask his pediatrician if you can give him a dose of Benadryl when he seems really congested and miserable. If it seems to relieve the symptoms (and not just make him sleepy!) it probably is seasonal allergies.

You could also try to get a HEPA filter /HEPA vaccuum for your house - unfortunately whether you take him outside or not, those allergens make their way into your house on your shoes, clothes, hair and the wind.

Good luck, and hope he feels better soon! Get the child off drugs and get this poor baby on something to boost antioxidants, detoxify and help increase immune function naturally.