This is very complicated. I am glad you are working with a pulmonologist. The enlarged lymph nodes could be a sign of Sarcoid. You could have endobronchial sarcoid, which acts like asthma. Most, but not all, wheezing is caused by asthma. Maybe what you call "infections" are not really infections but are asthma episodes. If your pulmonologist is right in saying that you have COPD, that could be a predisposing factor for recurrent infections.
When your internist said it might be job related, he or she may be referring to a latex allergy.
Finally, your sinuses may well be the source of these infections. I would recommend that you have a good evaluation of your sinuses by an ENT and that you try nasal washes. A nasal wash helps remove mucus and bacteria from the nose and sinuses. This can temporarily decrease your symptoms. A prescription nasal steroid spray can decrease nasal swelling and mucus production. This will prolong the decrease in sinus pressure and improve sinus drainage. A nasal steroid spray does not provide immediate relief of symptoms. It may require several weeks of routine use to become effective. To help the nasal steroid spray work better, use it regularly after doing the nasal wash. Please read our Nasal Wash MedFact at http://www.nationaljewish.org/medfacts/nasal.html for more information about this technique. Share this information with your doctor to see if doing nasal washes regularly would be helpful for you.
I too have the same problem and I am so tired of it.. as soon as the nose starts running.. i get an infection without a doubt and the last one took 2 rounds of antibiotics to get rid of.. finally i started with the salt water routine, have been ok for bout a week now but still have trouble breathing at night.
hope you feel better..
huffnpuff