In recent years, there has been “a significant increase in our understanding of the various aspects of allergy and its effect on various aspects of otolaryngology,” said Sarah Wise, MD, MSCR, professor of otolaryngology–head and neck surgery at Emory University in Atlanta and lead author for the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis.
Explore This IssueSeptember 2021
The unified airway theory posits that inflammation of the paranasal sinuses, eustachian tube, larynx, and parts of the oral cavity and pharynx may be related to allergic inflammation of the nasal cavities. After all, the mucosa lining the upper and lower airways is similar, and sensitized mast cells are present in these extranasal regions as well. Numerous research studies have elucidated possible links between allergies and ear and throat complaints, suggesting that clinicians should consider allergies when managing conditions such as eustachian tube disorder, chronic otitis media, and laryngitis.
“Intuitively, a lot of people long ago understood that mucosa exposed to inhaled allergens could be involved in allergic disease,” said Christopher D. Brook, MD, professor of otolaryngology–head and neck surgery at Harvard Medical School in Boston. “Now, there’s more and more research suggesting that a lot of people who are experiencing symptoms at disparate areas in the head and neck are actually experiencing allergies. It’s been objectively shown that if you introduce allergens into different areas of the head and neck, you can elicit an allergy response.”
Shifts in climate and weather patterns have extended allergy seasons in the Northern Hemisphere, and pollen levels have been increasing for the past 20 years, according to a 2019 study (Lancet Planet. 2019;3:e124-e131). As allergy seasons intensify and move beyond their historical temporal boundaries, patients are increasingly likely to experience allergy-related symptoms, although they (and their physicians) may not initially consider allergy as a possible cause or contributing factor.
Keeping allergies and all their effects in mind can help you effectively manage a variety of disorders.
A 2014 evidence-based review found nearly as many articles supporting a link between allergy and sinusitis as studies that showed no link at all. The authors concluded that the role of allergy in sinusitis was “controversial, with the level of evidence poor.” Allergy testing and treatment, they wrote, could be considered as an option (Int Forum Allergy Rhinol. 2014;4:93-103).
Dr. Wise, however, has noted a link between inhaled allergens and sinusitis. “We tend to see episodes of acute sinusitis and exacerbations of chronic rhinosinusitis fairly frequently during seasonal pollen increases,” she said. She has also noticed a connection between increased sinus problems and the start of seasonal decorating.
“Every year around the holidays, we’ll have people come in with a flare-up, and I’ll ask them if they’ve been putting up holiday decorations. There’s always a handful who say, ‘That’s funny. I was doing that last week,’” Dr. Wise said. She suspects that exposure to dust and mold—via decorations and boxes that have been stored in attics and basements—may be triggering allergic reactions in at least some of her patients.
Now, there’s more and more research suggesting that a lot of people who are experiencing symptoms at disparate areas in the head and neck are actually experiencing allergies. —Christopher D. Brook, MD
Research supports her supposition. A 2015 retrospective chart review of 998 patients who underwent allergy testing found that 60.9% of patients with chronic sinusitis had at least one positive specific IgE allergen test (Otolaryngol Head Neck Surg. 2016;154:41-45). Approximately 35% of allergic patients with chronic sinusitis had a sensitivity to dust, 35.6% were allergic to insects, 31.2% to tree pollen, 24.3% to weeds, 20.3% to grass, and 12.4% to mold.
“We don’t understand the exact pathophysiology yet,” Dr. Wise said, “but at least we have a baseline understanding and some data to support that.”
The link between allergy and sinusitis wasn’t acknowledged when Ayesha Khalid, MD, MBA, division chief of otolaryngology at Cambridge Health Alliance in Massachusetts, was a medical resident. “We talked about people’s allergies, but in a limited fashion,” she said. “We never really talked about their skin sensitivities or food intolerances.”
Experience and evolving research have taught Dr. Khalid to inquire about patients’ allergies. If a patient exhibits current evidence of allergic involvement, she may decline to perform a surgical procedure unless the patient agrees to also address his or her allergies. “Surgery,” she tells her patients, “isn’t going to cure you. It isn’t going to cure the lining of your nose or your sinuses.”
That’s a message some patients don’t want to hear. They may imagine sinus surgery as similar to a hip or knee replacement—do the surgery and in a few weeks that body part will be as good as new. But although removing nasal polyps may temporarily improve breathing for an allergic patient who has nasal polyps and chronic rhinosinusitis, the congestion (and polyps) will likely return if the allergies aren’t controlled.
“If we can’t embark on a treatment paradigm that includes allergy diagnosis and treatment, there’s no point in doing surgery,” Dr. Khalid said. “If a patient has evidence of severe allergic inflammation and we do surgery without addressing the allergies, it may take six months or six years, but eventually the surgery will ‘fail.’ It isn’t really that the surgery fails, however; it’s that the lining of the sinus isn’t working optimally.”
Currently, most cases of chronic laryngitis are attributed to laryngopharyngeal reflux. However, increasing evidence suggests that allergy may play a bigger role in vocal problems and chronic cough than previously suspected.
A 2019 review published in the Brazilian Journal of Otorhinolaryngology noted that individuals with allergic rhinitis have a higher prevalence of dysphonia than non-allergic individuals (Braz J Otorhinolaryngol. 2019;85:263-266). According to the same article, “singers with vocal symptoms are 15%-20% more likely to have allergic rhinitis than those without vocal symptoms.” A study from Taiwan found that individuals with allergic rhinitis were 2.43 times more likely to have laryngeal pathology than individuals who did not have allergic rhinitis (Healthcare. 2021;9: 36).
The Taiwanese study followed patients for several years and found that the median time to onset of laryngeal disease in those who were diagnosed with allergic rhinitis was 3.2 years. The authors estimated the cumulative one-, four-, and eight-year incidences of laryngeal pathology to be 3.0%, 8.1%, and 13.5%, respectively, for patients with allergic rhinitis.
The fact that laryngeal symptoms seem to emerge after years of allergic rhinitis suggests a causative role for allergy, with inflammation leading to hypersecretion of mucus, cough, dysphonia, and laryngeal edema.
The link between allergy and laryngeal symptoms isn’t usually apparent to patients, who typically present with cough, throat, or voice complaints. “Once you start asking them enough questions, though, they might realize that yes, they do have nasal stuffiness or sneezing or mild seasonal symptoms,” Dr. Brook said.
Consider referring patients with a history of allergy and those who have dense endolaryngeal mucus for allergy testing, particularly if previous treatments haven’t yielded lasting relief. “If they’ve tried everything under the sun and are looking for relief, I’ll often allergy test them and institute some sort of allergy treatment, which is quite often successful,” Dr. Brook said.
The 2015 retrospective chart review mentioned earlier also found that approximately 52% of patients with laryngeal symptoms who underwent allergy testing had at least one positive specific IgE allergen test (Otolaryngol Head Neck Surg. 2016;154:41-45). Patients with chronic laryngeal symptoms and positive allergy testing were most often sensitized to dust mites (63%).
Allergy testing may not be worth the effort or expense if the patient isn’t willing to pursue treatment. “If you’re looking at someone with some sort of chronic head and neck issue and you suppose allergy may be a part of that, you have to consider if the patient is bothered by it,” Dr. Brook said. “If they’re not bothered, it’s really not worth allergy testing them. If you’re not going to do anything with that information, it’s a waste of resources.”
It is helpful to have a close working relationship with an allergist; however, Dr. Khalid cautions that it may take some time to establish a mutual plan of care.
“I’ve had allergists send patients back to me and say, ‘Well, why don’t you take care of the sinuses first? Then send them back if they have issues,’” Dr. Khalid said. “I’ve had to work really hard over the last few years to persuade them that my surgery won’t succeed if the allergies aren’t well managed.”
Ideally, the otolaryngologist and allergist will work with the patient (and the patient’s primary care provider) to co-manage the patient’s symptoms and underlying pathology.
Several double-blind studies have shown that intranasal allergen challenges can result in Eustachian tube dysfunction, and “histologic studies have also shown that levels of eosinophils, CD3 T cells, interleukin (IL)-4 levels, and messenger RNA levels for IL-5 are increased at both ends” of the tubes, according to a 2017 review (Otolaryngol Clin North Am. 2017;50:1091-1101).
“When you have swelling in the nose and nasopharynx due to allergies, you can get edema and swelling around the Eustachian tube orifice,” said Peter C. Weber, MD, professor of otolaryngology–head and neck surgery at Boston University School of Medicine. “That can cause negative pressure within the middle ear, which can pull the eardrum medially. If that pull is strong enough or goes on long enough, the cells there can secrete fluid and you end up with serous otitis media.”
Although the relationship between allergy and otitis media with effusion (OME) has been “historically controversial,” a 2019 study from Iran that compared 37 children with OME to 52 children without OME found that allergic rhinitis prevalence was “noticeably higher” among OME patients than the control group (Iran J Otorhinolaryngol. 2019;31:209-215). While 24.3% of the children with OME had allergic rhinitis, only 5.8% of the control group did. Studies from Korea and Japan have also noted a link between allergy and OME. One Korean study found that 33.8% of children with OME also had allergic rhinitis, compared to 16% of children without OME (Int J Pediatr Otorhinolaryngol. 2013;77:158-161). Researchers in Japan have reported that more than 87% of patients with OME were found to be atopic or have allergy symptoms (Acta Otolaryngol. 1988;458:41-47).
A nasopharyngoscopy can be used to evaluate the ear, turbinates, nasopharynx, and Eustachian tube opening, “to see whether there’s any reactive tissue that might be a glimmer into a possible diagnosis of allergic rhinitis,” Dr. Weber said. Clinicians might note some “edema, hypertrophy, and boggy, pale mucosa,” he added.
If those signs are present, Dr. Weber may refer the patient for allergy testing. In some cases, he’ll treat the patient with antihistamines and nasal sprays before allergy testing in an effort to relieve the patient’s discomfort. After the patient is better and after they have been off medication for a while, allergy testing can reveal whether allergies may be a contributing factor. If so, immunotherapy may be beneficial. A 2008 study of 89 patients with OME (children and adults) revealed that all 89 subjects were atopic. Allergy immunotherapy significantly improved 5.5% and completely resolved 85% of chronic OME (Int J Pediatr Otorhinolaryngol. 2008;72:1215-1223).
When you have swelling in the nose and nasopharynx due to allergies, you can get edema and swelling around the Eustachian tube orifice. —Peter C. Weber, MD
Ménière’s disease may also be related to allergy. “Some people feel very strongly that it’s related to allergic disease, and others feel very strongly that it isn’t,” Dr. Brook said. “I’m probably somewhere in the middle.”
The first association of allergy and Ménière’s disease appeared in the literature in 1923. Since then, a few studies have reported a connection. A 2000 survey of 734 patients with Ménière’s disease revealed high levels of patient-reported allergies (nearly 60% reported possible airborne allergies; 40.3% had or suspected food allergies); 37% of the 734 patients had skin test-confirmed allergic disease (Otol Head Neck Surg. 2000;123:69-75). Cross-sectional surveys have shown that the prevalence of diagnosed allergy is up to three times higher in those with a history of Ménière’s disease compared to the general population (Otolaryngol Head Neck Surg. 2000;122:174-182).
A 2000 study by M. Jennifer Derebery, MD, reported significant improvement in tinnitus and vertigo in patients who had Ménière’s disease and underwent allergy desensitization and diet alterations (Otolaryngol Head Neck Surg. 2000;122:174-182). To date, however, no significant randomized, double-blind, placebo-controlled studies comparing Ménière’s disease patient outcomes with immunotherapy have been reported in the literature. However, as noted in a 2014 article, “the inclusion of allergy control as part of the treatment plan for Ménière’s disease is low risk to patients and should be considered for patients with indications that include history of seasonal or food allergy, past childhood or family history of allergy, bilateral Ménière’s symptoms, or a development of symptoms within a short time after exposure to food or inhaled allergen” (Curr Opin Otolaryngol Head Neck Surg. 2014;22:227-230).
Otolaryngology researchers are still delving into all the effects allergy can have on the body’s systems. Additional research into the extranasal manifestations of allergy would be useful as clinicians and patients navigate a future more likely to include a higher level of allergens.
Jennifer Fink is a freelance medical writer based in Wisconsin.