is caused due to broncho-constriction (obstruction of smaller airway passages) which is indicative of Hyper-responsiveness of air passages to an allergen.
The symptoms as mentioned in your post are related to this.
Nebulisation & Asthalin
inhaler provides symptomatic relief by causing broncho-dilation (dilating the smaller airway passages, relieving the obstruction & increasing airflow to lungs)
preparations can also be used as a maintenance therapy to relieve symptoms of seasonal allergies & asthma by reducing broncho-constriction.
If symptoms still persist...it will be better to consult a Pediatrician
And make sure that your son is well protected from cold
, dust & other allergens.
Wishing him a good health.
Thanks & take care.