Bronchitis and Asthma have similar symptoms.
But, Bronchitis is due to illness and usually follows a cold and is caused by a virus/bacterial origin.
Asthma, is a chronic disease and cannot be cured.
Bronchitis may lead to Asthma, in some cases. But not all people who have Bronchitis, will have Asthma.
In cases that Bronchitis leads to Asthma, this is called Acute Bronchitis or Asthmatic Bronchitis.
However, in the case of Asthma or Asthmatic Bronchitis, it is not a virus or bacteria that causes it. It is external environmental triggers, that causes it. Typically.
For your son... if he does not get better nor show improvement you NEED to go to the ER.
If he turns blue or his fingernails/skin, or if his chest is sucking in as he breathes, this is not good.
And, you NEED to make sure, he does not have Pneumonia. This is dangerous.
I have had Asthma, since I was a child.
I have also had Bronchitis.
I have also had a cold, that developed into Bronchitis... which then turned into Pneumonia.
So, there is no singular manner, in which chest illnesses, can or cannot develop. Or worsen.
But the bottom line is: you MUST keep up with his medication requirements.
This is, imperative.
The medications, also serves to strengthen his lungs and help it heal.
It is needed and necessary.
It can take awhile... for the person to recover, and for their lungs to heal... and for them to get better.
Try to have him stay away from anyone that is ill. Don't want him getting a relapse etc.
I, stay away from people that are sick, if I can. Because, I have Asthma. Which gets worse, when I am sick with a cold.