Hello A A,
Looks like it's also time to find another allergist. By the way, could your son be allergic to latex? my daughter is and NONE of the tests came back positive. if she touches anything that has latex, she's got asthma a couple of hours later.
one thing you can try is to give your son 1 tsp milk of magnesia (hide it in chocolate milk, etc.
http://www.asthmaworld.org/asthma-magnesium.htm
http://www.bodyandfitness.com/Information/Health/asthma.htm
http://www.medscape.com/viewarticle/483979
By the way, allergists and doctors know about magnesium use in asthma treatment. so this is nothing new... it's just the 'old' treatment (magnesium sulfate IV's) they even have ointments.
I even lathered my daughter's arms and legs with milk of magnesia - she didn't want to drink anything.
I told her doctor and allergist. The allergist was surprised that she responded to the mangesium because her asthma was allergy-induced.
I don't know if you noticed, but whenever your son has asthma, he's probably constipated too.
I also recommend chiropractic treatment.
Another thing to consider is what chemicals are you using for cleaning your house? for laundry, dishes, etc. do you spray air fresheners? plugins, etc? what type of hand soap, body soap, shampoo do you use. question every thing. see if you can find a definite pattern for when he gets sick.
you may want to try a very hypoallergenic diet for a few days and then start to re-introduce some foods and see how he does. Make a list of everything he eats and drink.
switch to natural cleaners. get all plants/flowers out of the house, steam his room. get bedding that reduces dustmites.
increase his omega-3 consumption.
increase his magnesium consumption.
keep him hydrated
skip cow milk/products for a while and see if it has an effect on him.
I hope this helps. I know how frustrating it can be. it took me over a year to figure out that it was latex that was getting my daughter sick. I even have a picture of her on her first birthday where she's got a balloon crown and holding on to some other balloon animal.
and you're right, it's starts w/ a stuffy nose, then cough and then it's a runaway train! follow your instinct! Good luck. ~C.~