Biomedical subjects
Robert M Naclerio
Publications and source records attributed to Robert M Naclerio.
Epithelial shedding is associated with nasal reactions to cold, dry air.
BACKGROUND: Cold, dry air (CDA) can cause symptoms of rhinitis and obstructive airway responses. The pathophysiology of these reactions is not understood. One hypothesis is that the respiratory mucosa of individuals with CDA sensitivity cannot compensate for the loss of water that occurs on exposure to the stimulus, leading to epithelial damage. OBJECTIVE: To test for an association between nasal reactions to CDA and the number of epithelial cells recovered in nasal fluids. METHODS: Ten CDA-sensitive subjects received nasal provocations with CDA and warm, moist air; 10 CDA-insensitive subjects received CDA; and 10 subjects with allergic rhinitis received allergen and diluent challenges. Nasal lavage cytology was performed at baseline and after the challenge. Symptoms were recorded and histamine, [3H]-N-alpha-tosyl-L-arginine methyl ester-esterase activity, tryptase, and albumin were assayed in nasal lavages. RESULTS: A 6-fold increase in nasal lavage epithelial cells was found in the CDA-sensitive group after CDA (P < .01), but not after warm, moist air. No changes were observed in the CDA-insensitive group, or after allergen or diluent in allergic rhinitis. CONCLUSION: Epithelial cell shedding accompanies clinical responses to CDA in the human nose. This supports the hypothesis that the airway mucosa of CDA-sensitive individuals cannot compensate for the water loss that occurs under extreme conditions leading to epithelial damage. CLINICAL IMPLICATIONS: A defect in mucosal water homeostasis may need to be considered in individuals who get excessive nasal symptoms when exposed to cold and dry, windy environment.
The effect of treatment with moxifloxacin or azithromycin on acute bacterial rhinosinusitis in mice.
OBJECTIVE: Acute bacterial rhinosinusitis, which is a major health problem, is treated with antibiotics. We developed a mouse model of acute bacterial rhinosinusitis to gain a better understanding of the pathophysiology of the disease. Our goal was to investigate the response to acute rhinosinusitis when treated with either a bactericidal or a bacteriostatic antibiotic. METHODS: C57BL/6 mice were infected intranasally with Streptococcus pneumoniae. One day after inoculation, the mice were treated with either moxifloxacin (bactericidal) or azithromycin (bacteriostatic). Different groups were euthanized during the first five days post-inoculation. Bacterial counts from nasal lavage culture and the cell markers GR1, CD11b, CD3, CD4, and CD8 in sinus tissue were evaluated by flow cytometry. RESULTS: Azithromycin led to rapid clearance of the bacteria and of the inflammation in contrast to placebo. Surprisingly, moxifloxacin showed a limited effect. Investigations of this limited effect of moxifloxacin suggested a high metabolic clearance, a low concentration at the site of infection, and low persistent post-antibiotic effects of moxifloxacin in mice. CONCLUSION: Our animal model of acute sinusitis has great utility for studying the disease, but the difference between mice and man must always be considered in making extrapolations from animal experiments to the human experience.
Effect of genetic background on the response to bacterial sinusitis in mice.
OBJECTIVE: To study the importance of ongoing allergen exposure and TH1/TH2 genetic background in augmented bacterial and inflammatory responses in allergic and infected mice. DESIGN: BALB/c and C57BL/6 mice were made allergic to ovalbumin. After 1 day of intranasal allergen exposure, they were inoculated intranasally with Streptococcus pneumoniae. The numbers of bacteria and inflammatory cells in the sinuses were determined, and nasal responsiveness to histamine was assessed. RESULTS: Infected BALB/c and C57BL/6 mice that received ongoing ovalbumin challenge following intraperitoneal sensitization showed significantly greater bacterial load and phagocyte level compared with the infected-only mice. Differences were diminished after the allergen challenge was stopped. Allergic and infected C57BL/6 mice showed fewer bacteria and phagocytes compared with the allergic and infected BALB/c mice. Surprisingly, in contrast to the nonallergenic C57BL/6 mice, the infected BALB/c mice showed a larger number of bacteria 28 days after infection. CONCLUSIONS: Ongoing allergic reaction augments bacterial load in both BALB/c and C57BL/6 mice and induces nasal hyperreactivity to histamine. Allergic and infected C57BL/6 mice show less allergic inflammation and bacterial load compared with allergic and infected BALB/c mice. Stopping allergen exposure reduces the response. Infected BALB/c mice, which favor a TH2 response, were less able to clear infection than C57BL/6 mice, which favor a TH1 response. Inflammation and bacterial load are affected by genetic background of mice and ongoing allergen stimulation.
Comparison of montelukast and pseudoephedrine in the treatment of allergic rhinitis.
OBJECTIVE: To compare montelukast sodium and pseudoephedrine hydrochloride in the treatment of seasonal allergic rhinitis. DESIGN: A 2-week, parallel, randomized, double-blind study with rolling enrollment. SETTING: Tertiary care medical center. PATIENTS: A total of 58 adult subjects with ragweed allergic rhinitis as documented by positive findings on a skin test to ragweed and history of symptoms during previous seasons. INTERVENTIONS: After recording their own baseline nasal symptoms, nasal peak inspiratory flow (NPIF), and diurnal and nocturnal rhinoconjunctivitis quality of life (QOL) scores, subjects were randomized to receive daily morning oral doses of either pseudoephedrine hydrochloride (240 mg) or montelukast sodium (10 mg) for 2 weeks. They recorded their nasal symptoms and NPIF twice daily during this time, and at the end of the study, they completed another QOL questionnaire and 2 tolerability profiles. MAIN OUTCOME MEASURES: Nasal symptoms, NPIF, QOL scores, and tolerability profiles. RESULTS: Both active treatments resulted in significant improvements from baseline in all symptoms of allergic rhinitis as well as in all the domains of the QOL questionnaires. When changes from baseline were compared between treatments, there were no significant differences except in the symptom of nasal congestion, for which pseudoephedrine was more effective than montelukast. Both treatments resulted in a significant increase in NPIF over baseline with no significant difference between treatments. Both drugs were well tolerated with no differences in the tolerability profiles between treatments. CONCLUSIONS: Pseudoephedrine and montelukast are equivalent in improving symptoms and QOL and increasing nasal airflow in patients with seasonal allergic rhinitis. The lack of the usual adverse effects in the pseudoephedrine group is ascribed to morning dosing.
Rhinosinusitis: developing guidance for clinical trials.
The Rhinosinusitis Initiative was developed by 5 national societies. The current guidance document is an expansion of the 2004 publication "Rhinosinusitis: Establishing definitions for clinical research and patient care" and provides templates for clinical trials in antimicrobial, anti-inflammatory, and symptom-relieving therapies for the following: (1) acute presumed bacterial rhinosinusitis, (2) chronic rhinosinusitis (CRS) without nasal polyps, (3) CRS with nasal polyps, and (4) classic allergic fungal rhinosinusitis. In addition to the templates for clinical trials and proposed study designs, the Rhinosinusitis Initiative has developed 6 appendices, which address (1) health outcomes, (2) nasal endoscopy and staging of CRS, (3) radiologic imaging, (4) microbiology, (5) laboratory measures, and (6) biostatistical methods.
Rhinosinusitis: Developing guidance for clinical trials.
The Rhinosinusitis Initiative was developed by 5 national societies. The current guidance document is an expansion of the 2004 publication, "Rhinosinusitis: Establishing definitions for clinical research and patient care" and provides templates for clinical trials in antimicrobial, anti-inflammatory, and symptom-relieving therapies for the following: (1) acute presumed bacterial rhinosinusitis, (2) chronic rhinosinusitis (CRS) without nasal polyps, (3) CRS with nasal polyps, and (4) classic allergic fungal rhinosinusitis. In addition to the templates for clinical trials and proposed study designs, the Rhinosinusitis Initiative has developed 6 appendices, which address (1) health outcomes, (2) nasal endoscopy and staging of CRS, (3) radiologic imaging, (4) microbiology, (5) laboratory measures, and (6) biostatistical methods.
Effect of montelukast on bacterial sinusitis in allergic mice.
BACKGROUND: In mice, allergic rhinitis augments the infectious and inflammatory response to Streptococcus pneumoniae-induced sinusitis. OBJECTIVE: To investigate the effects of cysteinyl leukotriene antagonism on the severity of bacterial infection. METHODS: We performed 3 parallel, placebo-controlled experiments. In the first, mice were ovalbumin sensitized and ovalbumin challenged to show the effects of montelukast on the allergic inflammation; in the second, we evaluated the effect of montelukast on S. pneumoniae infection; in the third, we used mice that were both allergic and infected. Montelukast was given starting 2 days after sensitization until the day before euthanasia. One day after drug treatment began, the mice were inoculated intranasally with S. pneumoniae in the infected groups. Nasal hypersensitivity was measured with histamine challenges before the first sensitization and on the day before euthanasia. On the fifth day after infection, mice were euthanized, nasal lavage was performed, bacteria were cultured, and inflammatory cells in the sinuses were quantified. RESULTS: Mice that were infected only tended toward having increased bacterial counts from nasal lavage in the montelukast-treated group. The mice that were allergic and infected experienced significantly higher bacterial counts (P < .05). All 3 montelukast treatment groups had significantly decreased eosinophil counts as well as T-lymphocyte counts. CONCLUSIONS: Montelukast reduces the manifestations of allergic rhinitis in mice. Surprisingly, montelukast led to an increase in bacterial growth in infected mice. This suggests an effect of the cysteinyl leukotrienes on the innate response to bacterial infection.
Persistent inflammation and hyperresponsiveness following viral rhinosinusitis.
OBJECTIVES: To develop a murine model of viral rhinosinusitis. STUDY DESIGN: Randomized, controlled, animal model. METHODS: Mice were intranasally inoculated with Sendai virus (SeV) or ultraviolet (UV)-inactivated virus. On days 3 and 10 postinfection, nasal lavage fluid was obtained for viral culture. On days 4, 10, and 38 postinfection, sinus mucosa was harvested and analyzed by flow cytometry for CD3-, CD4-, CD8-, CD25-, CD11b-, CCR3-, and GR1-positive cells. Nasal hyperresponsiveness to histamine challenge was measured on days 8 and 36 postinoculation. RESULTS: On day 3, viral cultures were positive from all SeV-inoculated mice but from none of the UV-inactivated mice (P<or=.0039). There was no growth of virus from either group on day 10. On day 4, flow cytometry on SeV-infected sinus cells showed a significant increase in macrophages (P<or=.03) and neutrophils (P<or=.02) compared with controls. This inflammation resolved by day 10. On day 38, mice inoculated with SeV had significantly more CD8+ (P<or=.044) and CD4+CD25+ (P<or=.017) cells than did controls. On day 8, there was a significant increase in both sneezing (P<or=.002) and nasal rubbing (P<or=.002) in the SeV-infected group to histamine challenge compared with controls. This difference continued to day 36. CONCLUSIONS: Inoculation with SeV results in an acute infection that resolves spontaneously within 10 days. Infected mice develop a significant increase in T-suppressor and T-regulatory cells after resolution of the acute infection, which persists for at least 38 days. The persistence of these T cells is associated with hyperresponsiveness to histamine. This mouse model has some parallels to chronic rhinosinusitis after a viral infection in humans and should allow us to clarify the pathophysiology of this disease.
Total IgE levels do not change 1 year after endoscopic sinus surgery in patients with chronic rhinosinusitis.
BACKGROUND: Total IgE levels positively correlate with the amount of mucosal thickening on sinus CT scans. Our objective was to investigate whether the levels of total serum IgE decreased 1 year after endoscopic sinus surgery in patients with chronic rhinosinusitis, suggesting that the total IgE was influenced by the sinus disease. METHODS: 55 patients about to undergo endoscopic sinus surgery for chronic rhinosinusitis were enrolled in a prospective clinical study. All patients had preoperative sinus computerized tomography (CT) scans and levels of total serum IgE measured before surgery and 1 year postoperatively. RESULTS: Preoperative total IgE levels showed a significant correlation with the extent of disease on sinus CT (r(s) = 0.413, p = 0.002). Total serum IgE levels did not show any statistically significant change from the preoperative values when measured 1 year postoperatively (324.25 +/- 217.30 ng/ml vs. 326.35 +/- 204.50 ng/ml; p = 0.61). CONCLUSIONS: The levels of total serum IgE do not change after sinus surgery for chronic rhinosinusitis. IgE levels in chronic rhinosinusitis may reflect a systemic factor in disease pathogenesis, and are probably not related to the amount of local inflammation within the sinuses.
Role of type 1 T helper cells in the resolution of acute Streptococcus pneumoniae sinusitis: a mouse model.
BACKGROUND: We examined the importance of the adaptive and innate immune responses in the resolution of an acute bacterial sinus infection in mice. METHODS: Recombinase-activating gene knockout (RAG-1(-/-)) (no lymphocytes) and C57BL/6 (wild-type) mice were infected with Streptococcus pneumoniae. For determination of the cell type involved, lymphocytes from mice were adoptively transferred into RAG-1(-/-), C57BL/6 (all lymphocytes), B cell-deficient, and T cell-deficient mice. The degree of infection and inflammation was determined by quantification of S. pneumoniae from nasal lavage and analysis of sinus tissue, respectively. RESULTS: In C57BL/6 mice, both the infection and inflammation resolved in 21 days, whereas neither resolved in RAG-1(-/-) mice. When C57BL/6 lymphocytes were adoptively transferred into RAG-1(-/-) mice, resolution of the infection and inflammation occurred. Mice without B cells were able to clear the infection, whereas mice without T cells could not clear it. In vitro stimulation of the draining lymph nodes of the infected mice by use of heat-killed S. pneumoniae led to the production of interferon (IFN)- gamma. Flow-cytometric analysis of lymphocytes obtained from sinus mucosa and draining lymph nodes showed an increase in the number of type 1 T helper cell-like cells over that in control mice. CONCLUSIONS: RAG-1(-/-) mice with innate immunity but no lymphocytes contain--but cannot clear--a bacterial sinus infection. Lymphocytes transferred to RAG-1(-/-) mice clear the infection. The sinus mucosa and draining lymph nodes show an increase in T cells generating IFN- gamma. These data demonstrate that T cells are essential in clearing an acute S. pneumoniae bacterial sinus infection.
Alpha-adrenoreceptor blockade with phenoxybenzamine does not affect the ability of the nose to condition air.
The primary function of the nose is to warm and humidify air. We have previously shown that raising nasal mucosal temperature by immersing feet in warm water increases the amount of water evaporated by the nose as air passes through it (nasal conditioning capacity; Abbott D, Baroody F, Naureckas E, and Naclerio R. Am J Rhinol 15: 41-45, 2001). To investigate further the effect of nasal mucosal temperature on nasal conditioning capacity, we raised the temperature through alpha-adrenoreceptor blockade by intranasally administering phenoxybenzamine. We hypothesized that blocking alpha-adrenoreceptors during inhalation of cold, dry air would lead to an increase in nasal blood flow, surface temperature, and nasal conditioning capacity, as measured by the water gradient. After appropriate pilot studies, we performed a double-blind, placebo-controlled, two-way crossover study in nine nonatopic, healthy subjects by studying the effect of treatment with intranasal phenoxybenzamine. Nasal mucosal temperature increased significantly after administration of phenoxybenzamine and was associated with a significantly smaller net decrease in nasal mucosal temperature after exposure to cold, dry air (P < 0.05). However, there were no significant differences in nasal conditioning capacity between treatments (P > 0.05). Phenoxybenzamine decreased the symptom of rhinorrhea after exposure to cold, dry air (P < 0.05), but congestion was not different between individuals given phenoxybenzamine and placebo (P > 0.05). Our data demonstrate that phenoxybenzamine, despite raising mucosal temperature and not affecting nasal volume, did not affect the ability of the nose to warm and humidify air.
Acute bacterial rhinosinusitis causes hyperresponsiveness to histamine challenge in mice.
OBJECTIVES: To develop a physiologic test of nasal responsiveness in mice and to evaluate whether mice with acute bacterial sinusitis develop nasal hyperresponsiveness. DESIGN: Several experimental studies will be described. The first was a titration pilot study. The second was a randomized, placebo-controlled study. The remainder were before-and-after trials. SPECIES: BALB/c or C57BL/6 mice. INTERVENTIONS: For these experiments, we exposed mice to histamine intranasally, then counted the number of sneezes and nose rubs as the primary outcome measure of nasal responsiveness. First, we constructed a dose-response curve. Second, we treated the mice with desloratadine, a histamine 1 receptor antagonist, prior to histamine exposure. Third, we challenged, with intranasal histamine, mice made allergic using 2 techniques. Fourth, we infected mice with Streptococcus pneumoniae to determine whether acute sinusitis causes nasal hyperresponsiveness to histamine exposure. RESULTS: Nasal histamine challenge led to a reproducible, dose-dependent increase in sneezing and nose rubs. The response to histamine exposure was blocked by desloratadine (P < or = .05). Allergic mice had a significant increase in responsiveness (P < or = .05) over baseline after exposure to antigen. Mice with acute sinusitis had a sustained increase in responsiveness, although less severe than after allergy, compared with baseline values that lasted 12 days after infection (P < or = .05). CONCLUSIONS: Nasal challenge with histamine is a physiologic test of nasal responsiveness. The hyperresponsiveness of allergic mice to histamine exposure parallels the response to nonspecific stimuli during the human allergic reaction. In addition, we showed that acute bacterial sinusitis causes nasal hyperresponsiveness in mice.
Evaluation of importance of Toll-like receptor 4 in acute Streptococcus pneumoniae sinusitis in mice.
OBJECTIVES: To investigate the effect of RC-527, a synthetic toll-like receptor 4 (TLR4) agonist, on stimulating the immune response before acute Streptococcus pneumoniae sinusitis in a mouse model, and to determine the importance of TLR4 in modulating the response to S. pneumoniae. Toll-like receptor 4 agonists have been shown to induce protective innate immune responses when administered before some bacterial or viral challenges in mice. DESIGN: We intranasally inoculated BALB/c, TLR4 complex-deficient C3H/HeJ, and wild-type C3H/HeOuJ mice with S. pneumoniae 24 hours after treatment with 10 or 1 microg of RC-527 or vehicle. Bacterial counts from nasal lavage culture and the cell markers GR1, CD11b, CD3, CD4, and CD8 in sinus tissue were quantified at postinoculation days 2, 5, and 14. MAIN OUTCOME MEASURE: Immune response induced by RC-527. RESULTS: Treatment with RC-527 induced an immune response through TLR4, as demonstrated by recruitment of phagocytes in uninfected wild-type C3H/HeOuJ mice, but not in TLR4 complex-deficient C3H/HeJ mice. The immune response was also demonstrated by a significant increase of CD3+, CD4+, and CD8+ T cells in infected and uninfected wild-type C3H/HeOuJ mice, but not in TLR4 complex-deficient C3H/HeJ mice. However, the enhancement of the immune response induced by the TLR4 agonist showed a limited effect on bacterial clearance. CONCLUSIONS: Our studies in mice suggest that stimulation of TLR4 plays a minor role in the overall response to S. pneumoniae infection of the upper airway, and stimulating this receptor before infection does not significantly enhance the immune response of immunocompetent mice to clear S. pneumoniae infection.
Increased nasal airflow with budesonide compared with desloratadine during the allergy season.
OBJECTIVE: To compare the effects of desloratadine, an H1-blocking antihistamine, and budesonide, an intranasal corticosteroid, on nasal peak inspiratory flow (NPIF) in patients with seasonal allergic rhinitis. DESIGN: We performed a randomized, double-blind, double-dummy, parallel study comparing oral desloratadine, 5 mg/d (n = 31), and budesonide, 32 mug/d per nostril (n = 30), for 2 weeks during the spring allergy season. MAIN OUTCOME MEASURES: Subjects recorded NPIF and nasal symptoms twice daily. Baseline measurements were obtained before initiation of treatment. The Rhinoconjunctivitis Quality of Life Questionnaire was completed at baseline and after treatment. RESULTS: Desloratadine and budesonide caused a significant increase in NPIF compared with baseline on the evening of the first dose (P < .01). Budesonide, however, led to a significantly greater increase in NPIF than did desloratadine when the change from baseline was compared for the entire treatment period (median, 475 vs 150 L/min; P = .01). Both treatments resulted in clinically significant reductions of the individual domains and overall scores on the Rhinoconjunctivitis Quality of Life Questionnaire (P < .01). There was a significant reduction in total symptom scores (P < or = .01) compared with baseline during all treatment days in both treatment groups, with no statistically significant differences between treatments (median, -60.0 vs -59.5; P = .67). CONCLUSIONS: Both treatments led to significant improvements in NPIF, but the improvement was greater with the intranasal corticosteroid. Both treatments improved quality of life and reduced symptoms. The difference between the objective and subjective outcomes probably reflects the small sample size, the low pollen counts for the season, and the greater variability in subjective compared with objective measures.
Treatment of nasal inflammation decreases the ability of subjects with asthma to condition inspired air.
We previously showed that individuals with seasonal allergy have a reduced ability to condition air, which was improved by nasal inflammation. We also showed that subjects with asthma have a reduced ability to condition air. Because individuals with asthma usually have inflammation in the nose, we hypothesized that treatment with an intranasal steroid would reduce nasal inflammation and further decrease nasal conditioning capacity. We performed a randomized, double blind, placebo-controlled, 2-way crossover study on 20 subjects with asthma comparing the effect of treatment with intranasal budesonide for 2 weeks on nasal conditioning. Treatment with budesonide caused no significant effect on nasal conditioning as compared with placebo. When we evaluated the subgroup of nonsmoking subjects, budesonide caused a significant reduction in nasal conditioning. We speculate that nasal inflammation in nonsmoking individuals with asthma increases the conditioning capacity and reducing it with an intranasal steroid worsens the ability of the nose to condition air. In addition, smoking causes an increase in nasal conditioning capacity by non-steroid-dependent factors. These observations help us understand the pathophysiology of nasal conditioning, but do not negate the positive clinical benefits of budesonide on treating nasal inflammation.
Comparison of the combinations of fexofenadine-pseudoephedrine and loratadine-montelukast in the treatment of seasonal allergic rhinitis.
BACKGROUND: Antihistamine-decongestant combinations are used routinely for the treatment of seasonal allergic rhinitis. Recently, the combination of an antihistamine and a leukotriene receptor antagonist has been shown to be efficacious. OBJECTIVE: To compare the 2 combinations in the treatment of seasonal allergic rhinitis. METHODS: This was a randomized, double-blind, double-dummy, parallel study in which patients with seasonal allergic rhinitis received either fexofenadine, 60 mg, and pseudoephedrine, 120 mg, twice daily, or loratadine, 10 mg, and montelukast, 10 mg, once daily, for 2 weeks. The Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) was completed at the beginning and end of the study. Patients recorded nasal symptoms and measured nasal peak inspiratory flow (NPIF) twice daily. Baseline measurements were obtained before initiation of treatment. RESULTS: Compared with baseline, both treatments resulted in statistically and clinically meaningful reductions of overall and individual RQLQ domain scores (P < .01) except for the sleep domain, for which only loratadine-montelukast led to significant improvement. There was a significant reduction in total symptoms (P < or = .05) compared with baseline on most treatment days in patients receiving both combinations. When the change from baseline was analyzed, there were no statistically significant differences in total symptoms between fexofenadine-pseudoephedrine and loratadine-montelukast (median, -28.5 vs -22.5; P = .33). There was a significant improvement in NPIF from baseline on all treatment days in both groups (P < .05), with no significant difference between treatments. CONCLUSIONS: Fexofenadine-pseudoephedrine and loratadine-montelukast have comparable efficacy in improving symptoms, RQLQ scores, and nasal obstruction in seasonal allergic rhinitis. The lack of improvement in sleep in the fexofenadine-pseudoephedrine group is probably related to insomnia, a known adverse effect of pseudoephedrine.
Role of allergy in rhinosinusitis.
PURPOSE OF REVIEW: Allergic rhinitis and rhinosinusitis are common diseases occurring in both children and adults that consume enormous amounts of health care dollars. In addition to its own costs, allergic rhinitis is considered a major predisposing factor for the development of rhinosinusitis. Whereas many authors suggest a clinical association between these two diseases, the mechanism of how allergic rhinitis predisposes to rhinosinusitis or affects the course of rhinosinusitis remains unclear. RECENT FINDINGS: Limited progress has been made in understanding the pathophysiologic mechanism involved in the interaction. Progress in immunologic technique emphasizes the importance of inflammatory cells, especially eosinophils, mast cells, and T lymphocytes, and their mediators. Some authors have proposed a role for neurogenic pathways, whereas others have focused on systemic involvement. Little progress has been made in intervention studies that support the importance of allergic rhinitis in altering the course of acute or chronic rhinosinusitis. SUMMARY: This paper reviews the limited new literature available to update knowledge that supports the association of allergic rhinitis with rhinosinusitis, mechanisms potentially underlying the association, and implications of this knowledge for therapy.