Elizabeth sends in the following situation...
I have a 2.5 y/o Siberian Husky. She does a lot of "reverse sneezing" and also hacking, coughing up phlegm and swallowing hard. We have taken her to the vet for this several times and they have done x-rays and blood tests and treatment for nasal mites, she doesn't have any abnormalities in her heart, lungs, chest, or anywhere else, she is otherwise healthy and up to date on all her shots. Her throat seems to be swollen; she can still bark, but wooing and howling seem to be more difficult. We've tried using an air filter and humidifier, but I think it may be an allergy to something in the house (mold in the walls or under the floor maybe, or possibly a sewage smell that has been prevelent since last winter) since she is ok outside and in other buildings. I keep the house super clean and wash her blankets regularly (with dye and fragrance free detergent and no softener) so I don't think it's dust. Allergy medicine helps a little with the sneezing, but not with the coughing or the phlegm. The only thing that has helped has been steroids, when she was on steroids she was fine. I know that it isn't good to keep a dog on steroids because of potential health risks, so is there anything else that would have the same anti-imflammatory effects as steroids without the harmful side effects? My vet hasn't been able to suggest anything besides different allergy medications and more tests and x-rays, but I can't afford to pay the hundreds or thousands of dollars those tests would cost.
Right off the bat this is a strange type of allergy situation. Most allergies in dogs present as skin disorders, especially irritation and itching. Allergic bronchitis is possible, but uncommon. However, based on your description I wonder if this is more of a medical "reaction" than an "allergy". Unfortunately, there isn't anything simple or easy that you can do at this point.
My first recommendation is to have allergy testing done. A general practitioner can send blood to an outside lab for analysis, and the cost is usually around $200-300. Intradermal testing can be done by a dermatology specialist, though the discussions I've had with specialist and a review of the literature leads me to believe that the two methods have very similar efficacy. Even though a skin disorder isn't the main problem, the tests will still identify a sensitivity to the tested allergens, including molds and mites. If you can discover a specific cause, you might be able to try and remove it from the environment with specialized cleaning of the ducts, mold removal, or hypoallergenic filters.
If the test doesn't give any specific answers or if you cannot eliminate something from your home, there aren't many choices. Antihistamines only work in mild allergy cases, and will likely not help your situation. Cyclosporines help if there is an allergy disorder, but aren't really anti-inflammatories. Unfortunately, the only effective reducers of inflammation are steroids. While I agree that chronic steroid use is a last resort and can cause many side-effects, I also think that they definitely have their place. If this is the only form of effective therapy, then you really don't have many alternatives.
I wouldn't ignore this situation and would really look closely into the underlying cause. There might be something harmful for the humans in the house, and your dog is particularly sensitive to it. Most people are familiar with the canaries in a coal mine analogy. For those who don't know the stories, coal miners would take canaries in cages into the mine. When the fumes became toxic, the canaries would die, warning the miners of the danger. Since a canary was smaller, it would succumb to the toxins before a human, giving the man a chance to leave before they had problems. Nowadays we call animals like this "sentinels", and look at them for a variety of situations. It's possible that your dog may be a sentinel for a mold or other problem that could affect the rest of the family. Look into this to help your dog and the people around her.