And such allergies may be more common than suspected. “Skin surveys show that if you pick people out of a crowd and skin test them for allergies, about twice as many test positive as have symptoms of allergy,” Dr. Gordon said. “We quote the incidence of allergy at 20 to 25 percent, but if you test randomly, about 40 percent test positive. Will they get symptoms later? That is an unanswered question.”
Explore This IssueOctober 2010
In a recent issue of Allergy, Asthma & Clinical Immunology, Jayant Pinto, MD, assistant professor of surgery and a specialist in sinus and nasal diseases at the University of Chicago Medical Center, pointed out that allergic rhinitis is quite common among older people (2010;6(1):10). He cited research from the 2005 National Center for Health Statistics report showing that 10.7 percent of individuals between 45-64 years of age, 7.8 percent of patients 65-75 years of age, and 5.4 percent of patients older than 75 are affected by allergic rhinitis.
Rhinitis, a hallmark of many geriatric allergies, can be caused by a multitude of conditions that produce inflammation of the nasal membranes. When the patient is older, however, the diagnostic challenge increases.
Physical changes to the nose and mucus membranes influence the symptoms of rhinitis in older patients, according to Dr. Pinto, whose research focuses on the physiology of the nose. As the nose ages, the septal cartilage weakens, and the nasal columella retracts, leading to changes in the nasal cavity, he said. He explained that as the mucosal epithelium atrophies, mucus may become thicker and clearance may decline, especially in people who become dehydrated, resulting in increased postnasal drip and cough.
Dr. Pinto said that an elderly patient who appears in his office usually has failed to respond to typical treatments for rhinitis and may have more than one problem. The patient may have a cerebrospinal fluid (CSF) leak, for example, or hormonal rhinitis or some other systemic disorder that affects the noseóor perhaps the cause is something in the environment.
In an effort to diagnose the problem, Dr. Pinto asks himself a series of questions: Does the patient have a higher exposure to allergens than patients who respond to treatment? Do environmental modifications have to be more aggressively pursued? Or is the patient in a non-allergic rhinitis category? Based on the answers, he attempts to choose a specific treatment or “pursue therapy by trial and error to improve symptoms,” he said.