I've been getting allergy shots for a couple of years now. I had been having more severe reactions every year, the worst in late spring/early fall as I ramped up my cycling activity. Symptoms included congestion, headache, nausea and dizziness. I fell over from dizziness on more than one occasion and vomited a few times as well. I missed a few days work every spring/summer from it. The last straw was when I got so sick (cough, sore throat, congestion) that I had to cut a camping vacation short and upon returning home, still needed to call in sick for a few days. I kept feeling worse and worse until the doctor tried antibiotics and that did the trick. I figure it had developed into a sinus infection. After that I decided enough was enough and that regular "treat the symptoms," drugs weren't cutting it. I got the pin cushion test and started the injections and the following year my symptoms were less severe. This year has been even a bit better. I still take allergy meds when needed but I haven't had the really bad attack in spring/summer and my symptoms are much more manageable. I recommend looking into it if you can't find relief with anti-histamines, pills and such.