HHi Manisha,
It is absolutely alright to use the nebuliser- do not be scared!
By this very small amount of medicine goes to the lungs straight rather than a large amount of medicine going to all over the body.Also side effects are less and effects are more!If there is no family history of
asthma or
allergy,he will get over from this as he grows by 7-8 years. All the best
Dr Uma