Singulair and reactive airway disease?

Hi,  My 28 month old son got a stuffy nose, no fever, and then had a wheezing episode 2 months ago.  He was given an inhaler of Albuterol and was diagnosed with Reactive Airway Disease.  Since then he has had a stuffy nose of and on and needed to use his inhaler on 4 occasions always preceded by the stuffy nose.  He will get congested, and at night if the congestion worsens he may start some mild wheezing and I'll give him his inhaler and he improves and won't need his inhaler again unless the stuffy nose worsens.  

Now he has a sinus infection, during which he had two mild wheesing episodes at night.  The doctor has perscribed an antibiotic and also Singulair.  I thought that Singulair was an asthma preventative.  If my son has not yet been diagnosed with asthma and we give him singulair and he improves; how will we be able to conclusively determine that his condition is asthma and not just the result of the infection that has been cleared up by the antibiotic?  

I want to make sure that he has the most appropriate treatment for his condition.  At this point, should he see a specialist?

Thanks!

[National Jewish]

It is easy to understand your confusion and concern. Your physician is treating the wheezing with these medications. He/She is not making any diagnosis at this time. If when the infection is gone and the Singulair is stopped the wheezing is gone, then this was probably simply due to the infection. If there is wheezing or coughing that starts again with the next infection or without it, then this problem should be evaluated for asthma.
Hope that helps.