DEAR DR. ROACH: For months, I have had a persistent cough that I have been unable to get help with. I saw an allergist about three years ago and was told I am allergic to dust mites (I understand a large number of people fit into this category). I was first referred to a lung doctor where X-rays showed that my cheek sinus drains were completely blocked, and then to an ear, nose and throat doctor, who also confirmed this diagnosis.

This ENT doctor recommended I have surgery to unblock the drains and clear out the sinus area. I understand that sinus drainage can cause coughing and wonder if this would still make me cough. I sometimes cough until I can cough up something, and this seems to stop my cough for a while. I was using a nasal rinse for a while until about two weeks ago when it caused my nose to bleed. The ENT doctor prescribed antibiotics and oral steroids that did not make any difference. It doesn’t seem to make any difference whether I’m home or sitting in the doctor’s office, I’m still coughing. What is the best way to deal with dust mite allergy?

— J.S.

ANSWER: There are many causes of chronic cough, but postnasal drip is at the top of the list. Dust mites are indeed a common allergen, and symptoms may include runny nose, watery eyes, sneezing and cough from postnasal drip.

Specific treatment for dust mites should include physical barriers, such as covers for pillows and mattresses, and sometimes for other soft surfaces, like furniture cushions, but this is only part of an effective strategy. Removing as many fabrics as possible (draperies, carpets, stuffed children’s toys) where dust mites can live is essential. Regular cleaning is necessary, and high efficiency particulate air (HEPA) filters for vacuuming have been shown to reduce dust mites. A low-humidity environment can be very effective in discouraging dust mites, and cooler air — especially at night — can reduce irritation of nasal passages caused by dry air. Many interventions for a prolonged period are necessary to reduce dust mite infestation and the symptoms associated with them.

This is critical, because the issue of the sinuses is probably secondary to ongoing allergic exposure. Fixing your sinuses will not fix your ongoing symptoms. Without control of the allergens, you will continue to have symptoms and may even develop sinus blockages again, no matter how good a job the surgeon does on your sinuses.

DEAR DR. ROACH: I am an 87-year-old man in good health. Recently my physician discovered that I was having atrial fibrillation. I had no symptoms. My pulse was 80. He placed me on Eliquis twice daily, which I am taking. I feel fine, but I dislike taking anticoagulants and prefer other treatment for my condition. Is there other treatment you recommend?

— H.A.S.

ANSWER: Atrial fibrillation is a common rhythm disturbance. Treatment is designed to reduce symptoms, prevent heart damage from too fast a heart rate, and prevent a stroke from a blood clot. Since you have had no symptoms and your heart rate is normal, you need no therapy to control your heart rate. However, you are at increased risk for stroke just because you are over 75 years old, and oral anticoagulation from apixaban (Eliquis) or another agent is strongly recommended. Without treatment, you have about a 4% risk of stroke per year. With treatment, your risk is only about 1%. It’s much riskier NOT to take the medicine.

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected] or send mail to 628 Virginia Dr., Orlando, FL 32803.