A., I am a respiratory therapist that is studying to become an asthma educator. Reactive airways disease is just another way to say asthma. For some reason doctors are hesitant to use the term asthma with small children, I suppose because it has such a negative stigma attached to it. One of the reasons that additional tesing has not been ordered for your child is because the way asthma is diagnosed is with testing called Pulmonary function testing. Unfortunately, children under the age of 6 can not perform the testing manuver properly, so they can not be tested until then. Also, because of the nature of asthma which can be an episodic disease, other things like chest x-rays are not diagnostic. In children younger than 6, a chronic or recurring cough and problems with allergies and other upper respiratory illnesses are what is used to diagnose asthma. I would say, your child has asthma. Now, here are some things you should know. Asthma is a chronic inflammatory disease. That means, it never goes away. You must be very mindful of the dangers of asthma which kills about 4000 people a year in the US. If your child ever has a blue or purple tint to his lips or nail beds, get him to an emergency room immediately. Other signs that he is in distress: If he is struggling to breathe, if he stops playing or talking, if you see the skin around his throat, ribs or abdomen being pulled or sucked in with each breath. Do not mess around with these signs. Since you have a nebulizer, when you do notice any difficulty with his breathing or coughing, give him a treatment. If you do not see definate improvement within fifteen minutes of the treatment, get him to a doctor or hospital. I don't want to scare you, but I do want you to be aware that asthma is a serious disease and you should be very careful. You should also try to become as educated about asthma as you can. You can go on-line to the American Lung Association website (google it) and you will find all kinds of valuable information there. Lastly, do not become discouraged. Your sons asthma can be controlled, and he can live a mostly normal life. You just need to find out what his triggers are so you can reduce or eliminate them, get him on a good medication regimen. If you would like more information, you can e-mail me directly at ____@____.com Good luck. D.