Can't Stand the Coughing!

My 2 year old had been coughing for 2 weeks. At this point, I am sure he has developed environmental allergies. I have established a pattern. When we go outside he is fine for about an hour. Then he starts to cough a bit. If we stay out he will sneeze a little and develop a runny nose. When we go inside the symptoms subside to an occasional cough. Until bed - then the coughing kicks up again and some mild wheezing begins. Oh the poor little guy, I can barely listen to him. Most night I awake in the middle of the night to hear him coughing in his sleep. We have an appointment with the allergist next week, so we just have to get through the next 4 days. I can not even give him antihistamines because he will need to have scratch tests done st his appointment. So we wait, and I try to keep him inside as much as possible. Which is next to impossible since it has been beautiful and everyone wants to play outside! They are calling for rain tomorrow. :)