Okay so he DID have allergic reactions to it.
He had itching/swelling. So, why is the Doctor saying to look for hives or difficulty breathing? To me, your son's reaction... can/may lead to that.
Then what?
Or could your son have had something, else, that caused that reaction?
Is the inhaler still un-expired?
There are also other types of Asthma inhalers....
I have Asthma... and the Albuterol has never caused me any side effects.
There are quick acting 'emergency' type inhaler medicines and 'maintenance' types. Albuterol, is quick acting. To open up the airways/quell constricting airways.
There is also Ventolin, and Xopenex... and other types. For example.
Some work for some and not for others.