DEAR DOCTOR: Last year, for four months, I smelled cigarette smoke all the time -- even though I wasn't near smokers. The problem went away, but now it's back. I can be in bed, in my kitchen, at the grocery store, even church. I have been diagnosed with benign paroxysmal positional vertigo. Is there a connection? If not, what's causing this?
DEAR READER: I can only imagine what a nuisance this is. The condition is called phantosmia, meaning the smelling of an odor that isn't actually there. Rest assured, you're not alone.
One survey of 3,603 people over the age of 40 found that 6 percent of people experience phantom odors. Another study, of 2,569 people ages 60 to 90, found that 4.9 percent reported phantosmia. The condition is more often reported by women than men, with many women having had a prior short-lived episode between the ages of 15 and 30. For the majority, the phantom odors are unpleasant, often described as the smell of something burned, spoiled, rotten or foul. Thus, the smell of cigarette smoke is not unusual. Symptoms can last from two minutes to 30 minutes at a time; fortunately, they're rarely chronic.
Phantosmia can have a variety of causes, some of them serious. The most common one is inflammation within the nasal cavity or within the sinuses. This is most likely in people who have chronic allergies or recurrent sinus infections, but the condition can also occur with nasal passage inflammation not related to allergies, such as that linked to exposure to solvents, ammonia, benzene, cigarette smoke and drugs inhaled through the nose.
Your diagnosis of benign paroxysmal positional vertigo could theoretically be linked to the condition in that this type of vertigo can be related to middle ear and Eustachian tube dysfunction, which in turn can be affected by nasal and sinus problems. Knowing whether you have a history of nasal congestion or sinus problems might shed light on this potential connection.
Trauma to the nose or the sinuses can also lead to phantosmia, as can head trauma that damages the areas of the brain that process smell. Speaking of the brain, the olfactory bulb located above the nasal cavity is full of nerves that send information about smell to the brain and, as we get older, this area can become damaged and lose many of its nerve cells. This loss can be especially significant in people with neurodegenerative diseases such as Alzheimer's, Parkinson's and Lewy Body dementia, all of which affect the olfactory bulb.
Blood pressure medications, such as beta blockers, calcium channel blockers and ACE inhibitors, can occasionally be linked to both loss of smell and phantosmia. Other potential causes include tumors within the brain or nasal cavity, as well as seizures.
Often, however, no cause can be found. This is termed idiopathic phantosmia and, on the plus side, it improves with time. In fact, 53 percent of patients have improvement or resolution of phantom smells after one year.
So, be encouraged that your symptoms could improve. In the meantime, try nasal rinses -- which could decrease the sense of phantom smells -- and work with your physician to identify, if possible, a cause for the problem.
Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles. Send your questions to email@example.com, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.