Mrs. C, 34, works as a clerk in a duplicating shop. When she consulted me about night wheezing and shortness of breath, the first question I asked was whether she had experienced the wheezing and chronic coughing at work. It is known that fumes from copy machines can cause such allergic reactions, as well as throat irritation.

Once it was established that she had never experienced any symptoms at work, I asked about her use of aerosol spray products, such as furniture polish, insect sprays and hairsprays, as well as inhaling tobacco smoke and burning incense in the house. Chemical sprays and tobacco smoke can cause wheezing in certain allergic individuals, and numerous case histories link their use to acute respiratory conditions.

Mrs. C said she did use several of these sprays, usually in the evening when she cleaned her apartment. I advised her to discontinue using them and to report back in two weeks. She did so, but the condition remained.

Other household allergens are feather dust from pillows and mite dust from old mattresses. In old mattresses, mites can multiply by the millions, and the dust produced by the scales they shed can cause allergic reactions. But Mrs. C was using a pillow with a synthetic fiber known as Dacron, which is non-allergic, and had just bought a new mattress.

Another medical condition that can cause chronic wheezing and coughing at night is reflux esophagitis. This condition is caused by acid in the stomach creeping up the food tube (esophagus) and dumping the acid into the windpipe (trachea), which results in wheezing and coughing. This condition is often missed and is treatable with the use of drugs that decrease acid in the stomach.

I asked Mrs. C about her eating habits before going to bed. She reported that she was on a diet and usually snacked only on health foods, a sample of which she had in her pocketbook. When I read the ingredients label on the package of mixed nuts and fruits, I knew I had hit pay dirt. The culprit was sulfites. This chemical is used as a preservative in many foods to maintain their freshness and color. I explained to Mrs. C that sulfur, in the form of sulfur dioxide , sodium bisulphite and sodium metabisulphite, as well as potassium bisulfite and potassium metabisulphite, can cause allergic reactions in some people. I advised Mrs. C to read all labels and to avoid foods with sulfites.

Some of the common foods in which sulfites are found include salad bar items, salad dressings, instant coffee and tea, cake mixes, frozen pie dough, frozen seafood, dried fruits, frozen potatoes, sauerkraut, cider, wine and wine coolers, along with a host of other items.

After reading labels carefully and avoiding sulfites, Mrs. C now sleeps peacefully without wheezing and occasionally is awakened by her husband’s cold feet.