I cannot offer any natural remedies, however, my Dr. just prescribed zyertec for my little one. She is a year and it hasn't affected her motor skills. I asked them if it would make her sleepy like the benedryl and he said no.
What is wrong with your little one? I think the natural remedy would depend on what is wrong?
I agree--it really depends on why you're using it. We use atarax because of a corn allergy, but both benadryl and atarax are very strong antihistamines and, personally, I would only use them to treat a reaction. We use the atarax very sparingly--it's not a daily maintenance medication.