thanks for your thoughts, and yes he does carry an inhaler with him. My problem with him is that he will not take his normal allergy medicine -claritin and advair when he feels well and then of course he gets into problems
What this could be is, if a person coughs and coughs, to where they can barely breathe, it can make a sensation where the whole body kind of stings, as if every blood vessel and nerve and lung bronchiole in the body is electric. I've always thought of it as an artery thing, the way it spreads, you can almost visualize the branches of vessels, and when a person coughs and puts a lot of stress on their heart and lungs, I think it could make the pressure of pumping blood push hard on the vessel walls. See, I've had these terrible coughs occasionally that do what you're describing, so from what I've experienced, I think your son should visit someone who can evaluate his pulmonary capabilities, his oxygenation, plus they would know if it was indeed the circulatory system that is hurting, or as you suggested maybe the nervous system, or perhaps his lungs and all its passageways.
I hate to tell a parent ANYTHING about how they're handling stuff, but your son MUST have a mist puffer to pull him out of this painful cough, it cannot be good for him to get such a bad attack. Also, there are medications that are relatively mild that can be prescribed by an asthma doctor where your son will be much less likely to react to allergic triggers. Since the main cause of this pain is because your son cannot get his breath, then could be there's a website on oxygen deprivation and what the sensations are, or even go to an asthma website and do a search for pain. Also, I do believe we've got an asthma forum, you'll have to look at the forum list and see what you can find, could be some people there are familiar with this violent coughing producing radiating pain in the body.
But I think I have experienced this thing your son has, and it's no fun, and in fact for me, I always believe I am just seconds away from falling down and passing out on account of I CANNOT BREATHE. It's an awful sensation, and the pain spreads throughout my chest, into my arms, which again tells me it's the heart or blood vessels somehow doing this.