Allergic rhinitis among the elderly poses a particularly difficult diagnostic challenge for the otolaryngologist. As people age, they undergo immunosenescence. The thymus, which produces T cells against new invaders, atrophies markedly after adolescence, and this decline results in a less robust immune response to bacteria, viruses and presumably allergens (J Pathol. 2007;211(2):144-156). Consequently, physicians have assumed that allergies should decline as people age.
But this may be an oversimplification, according to Karen Calhoun, MD, professor of otolaryngology at Ohio State University and president of the American Society of Geriatric Otolaryngology. One problem is that testing for allergies among older patients becomes less reliable due to immunosenescence.
“The skin becomes less reactive,” said Dr. Calhoun, co-editor of Expert Guide to Otolaryngology (American College of Physicians, 2001). “The typical prick test is done on the very outer level of the epidermis, and as people age, they have fewer and fewer reactive cells in that layer, but you can detect allergies with intradermal testing, which is done at a deeper layer where there are more reactive cells in everyone. The big message is: Allergies do happen in older adults.”
A Common Issue
Undertreating such allergies can impair quality of life, reduce work productivity and invite secondary complications such as sinusitis and sleep disturbances, especially in those patients with asthma, according to David M. Lang, MD, head of allergy and immunology and co-director of the Asthma Center in the Respiratory Institute at the Cleveland Clinic. He added that older people with asthma or chronic obstructive pulmonary disease (COPD) may find their symptoms aggravated by allergies.
In an article he wrote for the Geriatric Times (ìManagement of Allergic Rhinitis,î March/April 2002), Dr. Lang pointed out that by the year 2020, one in six people in the U.S. will be 65 or older, which means that proper recognition and management of allergic rhinitis in older adults will become increasingly important.
“For older adults with allergic rhinitis, avoidance measures combined with medication use [are] frequently effective,” he said. “If that’s not effective, then allergy shots can be considered, and, in select cases, you put patients on allergy immunotherapy if they don’t have an optimal or desired response to avoidance measures with medication.”
Bruce R. Gordon, MD, an otolaryngologist with a practice on Cape Cod, has noticed more and more cases of allergic rhinitis among his older patients.”ìI have a lot of people in their 70s and 80s who are on a lot of meds and often need immunotherapy because they have such bad allergy symptoms,” said Dr. Gordon, who has been practicing for 30 years. “We used to think that as people aged their allergies disappeared, but many more older people have allergies now, and their allergies are extending into very old age. In fact, people over 60 who never had trouble in their life are developing allergies.”
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.”
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.
Treating rhinitis in older patients involves a fundamental paradox of the aging immune system. “With age, autoimmune disorders can increase,” Dr. Pinto said. “The mechanism for that is not known, but one possibility is that there might be less tight regulation of immune responses leading to autoimmunity, a loss of tolerance to self.”
Intranasal steroids have become the first-line treatment for moderate to severe geriatric allergic rhinitis, in part because they are generally well tolerated by older patients, although they can aggravate nasal dryness and mucosal crusting. Dr. Pinto also advises radioallergosorbent (RAS) testing to confirm allergic rhinitis.
A Worldwide Increase
While no one knows what is causing the apparently worldwide increase in allergies, “there are a bunch of theories,” Dr. Gordon said. “For example, we’re too clean and we don’t get enough bacterial exposure. That’s the hygiene hypothesis. Chemical pollutants in our food, water and air are altering our immune response. Aromatic polycyclic hydrocarbons, for example, have been strongly linked to eczema, allergic rhinitis and asthma. Living indoors means we’re exposed to house dust allergens almost all the time. Diesel particles in the air are synergistic with allergens in triggering asthma. And modern food processing means we are constantly exposed to wheat, corn, soy and yeast.”
One of the more recent theories involves inadequate levels of vitamin D, leading to more asthma and respiratory allergies. Swiss scientists recently reported in Gerontology that low levels of calcitrol, a form of vitamin D, may play a role in geriatric allergic disorders (Mohrenschlager M, Ring J. [Published online ahead of print June 11, 2010]). Also, in an animal model, calcitrol was found to prevent allergic asthma.
“I recommend that my patients get their vitamin D checked, and it’s very rare I find an older adult with a normal level,” Dr. Gordon said. “A value of about 25 nanograms per milliliter is normal. A good level is between 50 and 80. It’s very rare to find an older patient over 50, and most are 20 or lower.”
While vitamin D is the “sunshine vitamin,” Dr. Gordon does not encourage older people to spend more time in the sun, however. “You need significant sun exposure to reach that level, and people can’t tolerate that much sun exposure for their entire lives because of the danger of skin cancer,” he said. “Take (vitamin) pills.”
While approximately 12 percent of the population in the U.S. is defined as geriatric according to the Federal Interagency Forum on Aging-Related Statistics, that number will increase to about 20 percent by 2030. “I think all otolaryngologists should begin to think about how otolaryngic diseases manifest in older patients, and how older patients differ from younger, because that’s going to be a growing part of our practice,” Dr. Pinto said.