Nasal Sensitivity Research Articles

An investigation of the correlation between functional and structural changes in tilted and non‐tilted high myopic eyes

PurposeTilted optic disc, a common finding in high myopic eyes, may affect visual field. Since the retinal defects often precede the visual field defects so evaluation of retinal layers thicknesses provide detailed information about the retina that may help us in earlier detection of pathologic changes in high myopic eyes. The aim of current study is the investigation of the correlation between functional and structural changes in tilted and non‐tilted high myopic eyes.MethodsFifty eight high myopic individuals were underwent detailed ophthalmic examination and divided into two groups according to the presence of the tilted optic disc. Correlation between visual field and retinal layers thicknesses in 20 patients (mean age of 28.95±7.22 years) with tilted optic disc were compared with 38 patients (mean age of 27.87 ± 6.08 years) without tilted disc using 30‐2 SITA standard program with Humphrey Field Analyzer – HFA II‐i and optical coherence tomography, respectively. Correlation of functional and structural findings was evaluated in 10 central degrees in four matched quadrants.ResultsAlthough there was a relative correlation between structural and functional tests in all quadrants but the most significant correlation was related to the nasal threshold sensitivity and temporal total average thickness in tilted group. (r = −0.55) The results showed that with decreasing the visual field sensitivity, the ganglion cell layer thickness decreased but retinal nerve fibres layer thickness increased in some quadrants.ConclusionsThe results showed relative correlation between structural and functional tests but the structural findings presented the defects earlier than functional findings. Therefore, the structural investigation in tilted myopic eyes suspected to visual field defect is recommended.

Response to Nonallergenic Irritants in Children With Allergic and Nonallergic Rhinitis.

PurposeNonallergenic irritants can aggravate the symptoms of rhinitis. We investigated the clinical responses of children with allergic rhinitis (AR) and nonallergic rhinitis (NAR) to nonallergenic irritants, and identified factors associated with these responses.MethodsChildren with chronic rhinitis (n=208) were classified as having AR or NAR based on the presence of aeroallergen-specific IgE. Healthy controls (n=24) were recruited for comparison. The Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines were used to classify patients, and their irritant score (0-21 points) and current symptom score (5-35 points) were measured. Subjects with irritant scores ≥3 and <3 were classified as having irritant and nonirritant rhinitis, respectively.ResultsThe mean age of enrolled subjects was 6.8 years (range: 1.8-16.0 years). The AR and NAR groups had similar irritant scores (P=0.394) and proportions of subjects with irritant scores ≥3 (P=0.105). Irritant score correlated positively with symptom score (P=0.005), and the proportion of subjects with irritant scores ≥3 was greater in children with moderate-severe rhinitis than in those with mild rhinitis (P=0.046). Multiple logistic regression analysis indicated that the presence of atopic eczema increased the risk for sensitivity to a nonallergenic irritant (aOR=2.928, 95% CI 1.567-5.473, P=0.001).ConclusionsResponse to a nonallergenic irritant was useful for gauging the severity of rhinitis, but not for differentiating AR from NAR. AR and NAR patients with atopic eczema may increase nasal sensitivity to nonallergenic irritants.

Subjective changes in nasal patency after chewing a menthol-containing gum in patients with olfactory loss

Conclusion: The subjective increase in nasal patency after oral menthol application depends on olfactory function. In patients with relatively low olfactory sensitivity, this effect is small or absent. It was hypothesized that this may also modulate the sensation of nasal blockage. Objective: Menthol stimulates the nasal trigeminal nerve, resulting in a subjectively increased nasal airflow and patency without objectively measurable changes. Patients suffering from olfactory impairment also express a reduced nasal trigeminal sensitivity. The aim of this investigation was to examine the effect of menthol on nasal patency ratings in a group of patients suffering from olfactory dysfunction. Methods: A group of 92 patients with olfactory impairment was included in this study. Olfactory function was assessed using the ‘Sniffin’ Sticks.’ Patients were instructed to chew a menthol-containing gum for 30 s, after which they rated the change in nasal patency on a categorical scale. Results: Patients who rated the change in nasal patency as pronounced scored higher on the Sniffin’ Sticks olfactory test compared to patients who experienced little or no change in nasal patency after chewing the menthol-containing gum. On average, similar changes could be observed for all etiologies of olfactory impairment included in this study.

Nasalance and nasality of tracheoesophageal speech in total laryngectomee

The objective of this study was to determine the rates of nasalance for total laryngectomized users of a tracheoesophageal voice prosthesis and correlate them with the findings of auditory-perceptual assessment of nasality. In this study, 25 total laryngectomized users, including 20 men and five women, with a mean age of 63 years old participated. All the participants had a tracheoesophageal voice prosthesis and underwent treatment for the rehabilitation of tracheoesophageal communication. These patients were submitted to nasalance assessment using nasometry and auditory-perceptual evaluation of nasality and were rated by trained speech therapists. The nasalance values obtained for nasal (59.92%) and oral (18.64%) sentences were within the normal limits for laryngeal speakers of Brazilian Portuguese language. It was possible to observe the presence of nasality in nasal sentences and its absence in oral sentences among most speakers. Specificity was found to be 100% for nasal sentences and sensitivity was 100% for oral sentences. It was not possible to calculate these values for the oral sentences. Total laryngectomized patients with tracheoesophageal voice prostheses have adequate vocal nasality compatible with nasometry rates.

Sublingual immunotherapy in children with allergic rhinoconjunctivitis mono-sensitized to house-dust-mites: A double-blind-placebo-controlled randomised trial

Although sublingual immunotherapy (SLIT) has been demonstrated to be a safe and efficient treatment in children with seasonal allergic rhinitis (AR), there is little evidence on the efficacy of SLIT with house-dust-mite (HDM) extract in children with isolated perennial AR. We sought to assess the clinical efficacy and safety of HDM-SLIT in children with isolated allergic rhinitis-conjunctivitis mono-sensitized to HDM without asthma symptoms. Twenty-two children (aged 5-10 years) with perennial AR and conjunctivitis symptoms mono-sensitized to Dermatophagoides pteronyssinus and Dermatophagoides farinae were enrolled. During a 2 months run-in period, symptom and medication scores, lung functions, bronchial hyperreactivity, nasal provocation and skin prick tests were evaluated. Subjects were randomized to active or placebo using a double-blind method. A total of eighteen subjects were randomised to receive either active SLIT or placebo for 12 months. Daily symptom and medication scores, baseline lung functions, bronchial hyperreactivity, nasal provocation and skin prick tests were recorded and re-evaluated at the end of treatment. After one year of treatment, no significant differences were detected in the between groups and within group comparisons based on total rhinitis symptom/medication scores (p > 0.05). Skin reactivity to Dermatophagoides pteronyssinus was significantly reduced in HDM-SLIT compared to placebo group (p = 0.018). A significant reduction in nasal sensitivity was observed in SLIT group after one year treatment when compared to baseline (p = 0.04). Total conjunctivitis symptoms were reduced significantly in both active and lacebo group at the end of treatment compared to baseline. The proportion of patients with non-specific bronchial hyperreactivity increased to almost 3-fold in placebo group compared to baseline. HDM-SLIT was not superior to placebo in reducing isolated rhinoconjunctivitis symptoms within 12 months of treatment. However, HDM-SLIT has a modulating effect on allergen-specific nasal and skin reactivity in isolated perennial AR children. The trial was registered at Anzctr.org.au number, ACTRN12613000315718.

Samter's triad in childhood: a warning for those prescribing NSAIDs

Aspirin-exacerbated respiratory disease (AERD) has been recognized in adults with chronic asthma. Samter's triad is a subset of AERD where adult patients develop nasal polyps, asthma, and sensitivity to aspirin. This condition is thought not to occur before the third decade of life. We report a 13-year-old boy with nasal polyps who suffered a life-threatening exacerbation of asthma during a graded aspirin challenge. Resuscitation required positive pressure ventilation and inotropic support. Our observations confirm that classical Samter's triad can occur in children. We suggest that graded aspirin challenges in children are undertaken in a facility with equipment and staff trained for resuscitation. Consideration should be given to this rare complication when prescribing nonsteroidal anti-inflammatory drugs in the perioperative period. Suspicion of this condition merits referral to an immunologist for desensitization to aspirin.

Brief Report: Preliminary Evidence of Reduced Sensitivity in the Peripheral Visual Field of Adolescents with Autistic Spectrum Disorder

A number of studies have demonstrated atypical perception in individuals with ASD. However, the majority of these studies have presented stimuli to central vision. The aim of the study presented here was to test the sensitivity of peripheral vision in ASD. This was achieved by asking participants to detect brief flashes of light presented between 30 and 85 degrees away from fixation. We found that participants with ASD detected fewer ligh-flashes than the control participants. This deficit was more pronounced in the nasal hemifield than the temporal hemifield. We suggest that the imbalance between nasal and temporal hemifield sensitivity may contribute to the peripheral-field stimulation and lateral glances that are observed in ASD.

Nasal insulin changes peripheral insulin sensitivity simultaneously with altered activity in homeostatic and reward-related human brain regions

Impaired insulin sensitivity is a major factor leading to type 2 diabetes. Animal studies suggest that the brain is involved in the regulation of insulin sensitivity. We investigated whether insulin action in the human brain regulates peripheral insulin sensitivity and examined which brain areas are involved. Insulin and placebo were given intranasally. Plasma glucose, insulin and C-peptide were measured in 103 participants at 0, 30 and 60 min. A subgroup (n = 12) was also studied with functional MRI, and blood sampling at 0, 30 and 120 min. For each time-point, the HOMA of insulin resistance (HOMA-IR) was calculated as an inverse estimate of peripheral insulin sensitivity. Plasma insulin increased and subsequently decreased. This excursion was accompanied by slightly decreased plasma glucose, resulting in an initially increased HOMA-IR. At 1 h after insulin spray, the HOMA-IR subsequently decreased and remained lower up to 120 min. An increase in hypothalamic activity was observed, which correlated with the increased HOMA-IR at 30 min post-spray. Activity in the putamen, right insula and orbitofrontal cortex correlated with the decreased HOMA-IR at 120 min post-spray. Central insulin action in specific brain areas, including the hypothalamus, may time-dependently regulate peripheral insulin sensitivity. This introduces a potential novel mechanism for the regulation of peripheral insulin sensitivity and underlines the importance of cerebral insulin action for the whole organism.

The Effect of Menthol Vapor on Nasal Sensitivity to Chemical Irritation

Among other effects, menthol added to cigarettes may modulate sensory response to cigarette smoke either by masking "harshness" or contributing to a desirable "impact." However, harshness and impact have been imprecisely defined and assessed using subjective measures. Thus, the current experiments used an objective measure of sensitivity to chemical irritation in the nose to test the hypothesis that menthol vapor modulates sensitivity to chemical irritation in the airways. Nasal irritation thresholds were measured for 2 model compounds (acetic acid and allyl isothiocyanate) using nasal lateralization. In this technique, participants simultaneously sniff clean air in one nostril and chemical vapor in the other and attempt to identify the stimulated nostril. People cannot lateralize based on smell alone but can do so when chemicals are strong enough to feel. In one condition, participants were pretreated by sniffing menthol vapor. In a control condition, participants were pretreated by sniffing an odorless blank (within-subjects design). Pretreatment with menthol vapor decreased sensitivity to nasal irritation from acetic acid (participants required higher concentrations to lateralize) but increased sensitivity to allyl isothiocyanate (lower concentrations were required). The current experiments provide objective evidence that menthol vapor can modulate sensitivity to chemical irritation in the upper airways in humans. Cigarette smoke is a complex mixture of chemicals and particulates, and further work will be needed to determine exactly how menthol modulates smoking sensation. A better understanding could lead to treatments tailored to help menthol smokers quit by replacing the sensation of mentholated cigarettes.

Is individual nasal sensitivity related to cellular metabolism of formaldehyde and susceptibility towards formaldehyde-induced genotoxicity?

Forty-one volunteers (male non-smokers, aged 32 ± 9.6 yrs) were tested for susceptibility towards unspecific nasal irritation (sensitivity towards CO 2) in order to define subgroups of hypersensitive and hyposensitive subjects. Blood samples were taken and the expression (mRNA level) of the GSH-dependent formaldehyde dehydrogenase gene ( FDH, identical to alcohol dehydrogenase 5, ADH5; EC 1.2.1.46) was measured in leukocytes by quantitative real-time RT-PCR with TaqMan probes. FDH is the most important enzyme for the metabolic inactivation of FA. Blood samples were exposed to 150 μM formaldehyde (FA) for 2 h and the induction of DNA–protein crosslinks (DPX) in leukocytes was measured by means of a modification of the alkaline comet assay (i.e., by assessing the reduction of DNA migration induced by γ-radiation). Removal of DPX was determined by the abolition of FA-induced reduction in DNA migration within 4 h after the end of the exposure. Furthermore, the induction of sister chromatid exchange (SCE) in cultured lymphocytes was studied after treatment of whole blood cultures with FA (150 μM). A correlation analysis was performed for all parameters tested for the whole study group and for hypersensitive and hyposensitive subgroups. The results indicate that despite large differences in CO 2-sensitivity, the susceptibility towards nasal irritation was not related to the induction of genotoxic effects (DPX, SCE) in peripheral blood or to the protection of blood cells against FA-induced effects (expression of FDH, repair capacity for FA-induced DPX). There was no correlation between CO 2-sensitivity and the expression of FDH. There was also no close correlation between the various indicators of cellular sensitivity towards FA-induced genotoxic effects and no subgroups were identified with particular mutagen sensitivity towards FA.

Nasal tactile sensitivity in allergic rhinitis

Conclusion: These preliminary data show a decrease in nasal tactile sensitivity and point out interesting aspects of the nasal chronic inflammatory condition in allergic rhinitis. Objectives: The aim of this study was to evaluate the effects of allergic rhinitis on nasal tactile sensitivity during the intercritical period. Methods: A total of 70 patients aged between 18 and 67 years (average 42 years), with a positive history of allergy caused by seasonal outdoor allergens, were included (group A). Patient outcome was assessed by the nasal monofilament test: a set of 20 Semmes-Weinstein monofilaments was used to detect nasal sensitivity for both nasal cavities. The sensitivity threshold was recorded as the minimum monofilament size with which patients could detect at least two of three stimuli. Results: When compared to the control group (group B), subjects in group A required a significantly (p < 0.05) higher stimulus to trigger a touch response in the monofilament test, for both the inferior (195.1 ± 0.39 mg vs 67.7 ± 0.19 mg) and middle turbinate (108.7 ± 0.23 mg vs 67.7 ± 0.19 mg).

The Influence of Environmental Exposure to Formaldehyde in Nasal Mucosa of Medical Students during Cadaver Dissection

Environmental exposure to formaldehyde is commonly associated with clinical symptoms such as mucosal irritation and olfactory disorders. However, the impact of such exposure on the development of mucosal inflammation and its outcome has not been carefully evaluated. The observational non-comparative study was planned. The study population consisted of group of 41 medical students who had signed up for a cadaver dissection course as part of their gross anatomy teaching at the school of medicine Chiba University in Japan. During such dissection course, the students are exposed to variable levels of environmental formaldehyde routinely employed for the preservation the cadavers. The subjects were evaluated by a detailed medical examination. We measured their serum IgE levels. In addition, an olfaction test and nasal mucosal sensitivity to histamine was serially determined, immediately before and after the course and 6 months after the completion of the course. Olfactory abnormalities were observed in 13/41 (32%) subjects and increased nasal mucosal hypersensitivity to histamine was observed in 17/41 (41%) during and immediately after completion of the course. These subjects had evidence of preexisting allergic rhinitis. 6/41 (15%) other students with no prior evidence of allergic rhinitis also exhibited formaldehyde associated clinical symptoms during the dissecting course. However, the symptoms disappeared upon completion of the course in all subjects studied. Temporary abnormalities in the olfaction test and increased nasal mucosal hypersensitivity to histamine were observed in a few students with preexisting allergic rhinitis after environmental exposure of high concentrations of formaldehyde. These effects appeared to be transient.

Nasal tactile sensitivity in elderly

Conclusion: Although older people varied widely in tactile sensitivity, our results show that tactile thresholds increased with age. Objectives: The aim of this study was to evaluate the effects of aging on nasal tactile sensitivity. Methods: A total of 160 healthy patients aged between 50 and 90 years were included. According to their age, patients were divided into groups (A, B, C, D, E, F, G, and H). From the age of 50, each group included subjects with an age range of 5 years (i.e. group A, 50–55 years; group B, 56–60 years, etc.). Each patient's outcome was assessed through the nasal monofilament test: a set of 20 Semmes-Weinstein monofilaments was used to detect nasal sensitivity for both nasal cavities. The sensitivity threshold was recorded as the minimum monofilament size from which patients could detect at least two of three stimuli. Results: In groups D (66–70 years), E (71–75 years), F (76–80 years), G (81–85 years), and H (86–90 years) a significantly (p < 0.05) higher stimulus (171.1 ± 0.34 mg vs 67.7 mg, 167.01 ± 0.31 mg 67.7 mg, 166.54 ± 0.28 mg 67.7 mg, 201.24 ± 0.43 mg 67.7 mg, 165,87 ± 0.27 mg 67.7 mg) was required to trigger a touch response in the monofilament test.

Correlation Between Eosinophilia and Nasal Features in Allergic Rhinosinusitis

A characteristic feature of nasal allergy is local accumulation of inflammatory cells, particularly mast cells and eosinophils, and their mediators, which have been implicated to be responsible for symptoms and signs of allergies. This prospective study tested the hypothesis that severity of nasal symptoms at presentation was related to the presence of nasal eosinophilia, using consecutive patients with allergic rhinitis attending the outpatient Department of Otorhinolaryngology, University College Hospital, Ibadan, Nigeria, between March and December 2008. Excluded were those who had commenced antihistamine and similar antiallergy drugs. Nasal eosinophilia, skin sensitivity, sinus radiograph, and clinical features were graded using standard classification. The study was composed of 49 subjects (28 males and 21 females). The subjects’ age ranged from 7 to 53 years (mean ± SD: 28 ± 4 years). Nasal eosinophilia and abnormal skin sensitivity response were seen in 41 (83.8%) and 37 (75.5%) subjects, respectively. Rhinorrhea, sneezing, and nasal obstruction constituted 42 (85.7%), 31 (63.3%), and 21 (42.9%), respectively, while inferior turbinate enlargement and radiological involvement were seen in 29 (59.2%) and 36 (73.5%) patients. The Spearman correlation test revealed a significant association between nasal smear eosinophilia and rhinorrhea (P = .008) and sneezing (P = .04), although there was no significant association with other variables. The authors conclude that the degree of nasal eosinophilia may be useful in predicting the severity of rhinorrhea and sneezing among the clinical features of nasal allergy.

Allergen immunotherapy

Specific immunotherapy (SIT) involves the administration of allergen extracts to achieve clinical tolerance of those allergens that cause symptoms in patients with allergic conditions. Immunotherapy is effective in patients with mild forms of allergic disease and also in those who do not respond well to standard drug therapy. Most SIT is given by means of injection, but there is increasing interest in performing SIT through the sublingual route. SIT remains the treatment of choice for patients with systemic allergic reactions to wasp and bee stings and should be considered as an option in patients with allergic rhinitis, asthma, or both. SIT can modify the course of allergic disease by reducing the risk of new allergic sensitizations and inhibiting the development of clinical asthma in children treated for allergic rhinitis. The precise mechanisms responsible for the beneficial effects of SIT remain a matter of research and debate. An effect on regulatory T cells seems most probable and is associated with switching of allergen-specific B cells toward IgG4 production. Few direct comparisons of SIT and drug therapy have been made. Existing data suggest that the effects of SIT take longer to develop, but once established, SIT achieves long-lasting relief of allergic symptoms, whereas the benefits of drugs only last as long as they are continued.

HLA antigens, nasal polyps and asthma

HLA antigens, nasal polyps and asthma HLA typing has been performed on a selected series of 29 patients with nasal polyps, with or without asthma. Despite the small series there was a significant increase in the haplotype A1/B8 in patients with both nasal polyps and asthma. No association was found in those with polyps alone. However, those with both conditions, who were positive for A1/B8, had more severe polyp disease. Three out of 4 patients with nasal polyps, asthma and sensitivity to aspirin were positive for A1/B8. In patients with nasal polyps, tissue typing might be of use in predicting both those who are most at risk of developing asthma, and also those who are most likely to have severe polyp disease. The association of A1/B8 with severe polyp disease and asthma, may imply that abnormalities of immune response are likely to be associated with the pathogenesis of both conditions.

Clinical effects of immunotherapy with genetically modified recombinant birch pollen Bet v 1 derivatives

Birch pollen and pollen from related trees of the Fagales order are a major cause of allergic rhinitis, conjunctivitis, and asthma through the spring season in northern and central Europe. To investigate the clinical effects of injection immunotherapy with genetically modified derivatives of major birch pollen allergen Bet v 1 on pollen-induced allergic symptoms. A three-arm double-blind placebo-controlled immunotherapy study was conducted with one pre-seasonal course of treatment using two derivatives of Bet v 1, namely a recombinant Bet v 1 trimer and an equimolar mixture of two recombinant Bet v 1 fragments together representing the whole protein sequence. Analysis of local and systemic adverse events was performed for 124 patients who had received at least one dose of medication. Clinical efficacy was monitored by symptom medication scores and interval scoring in the per protocol-treated population (n=84). In addition, skin and nasal provocation responses and allergen-specific antibodies were assessed. There were trends towards improvement in the subjects' well-being and clinical symptoms (nasal scores), although comparisons with a placebo group did not show statistical significance in the main end-point, the combined symptom medication score. Reductions in skin and nasal sensitivity were observed for some subjects with a trend for the Bet v 1 trimer to be more effective than the fragments. Treatment induced strong IgG1 and IgG4 allergen-specific antibody responses. Local injection-site reactions were most frequent in the trimer group affecting 59.5% of patients as opposed to 37.8% and 30.6% in the fragment and placebo groups, respectively. Systemic reactions were elicited more frequently by fragments. A large proportion of adverse side-effects appeared hours following injections, and might be attributable to concurrent exposure to related pollens. Single courses of injection immunotherapy with Bet v 1 allergen derivatives showed trends towards improved well-being and reduced reactivity to specific allergen provocation, but did not yield significant improvement in the combined symptom medication score in this study.

Upper airways reactions to cold air

Cold air-induced rhinitis is a common complaint of individuals with chronic allergic or nonallergic rhinitis and those with no chronic nasal disease. It is characterized by rhinorrhea, nasal congestion, and nasal burning that appear within minutes of exposure to cold air and dissipate soon after exposure is terminated. The symptoms of cold-air rhinitis are reproduced experimentally with nasal cold-air provocation. This procedure has shown that nasal mast cell activation and sensory nerve stimulation are associated with the development of nasal symptoms. Sensory nerve activation generates a cholinergic reflex that leads to rhinorrhea; therefore, anticholinergic agents are highly effective in treating cold-air rhinitis. Experimental data suggest that individuals with nasal cold-air sensitivity may have reduced ability to compensate for the water loss that occurs during exposure to cold air. Therefore, the symptoms of cold air-induced rhinitis may reflect the activation of compensatory mechanisms to restore mucosal homeostasis.

Evaluation of Trigeminal Sensitivity to Ammonia in Asthmatics and Healthy Human Volunteers

Asthmatics often report the triggering or exacerbation of respiratory symptoms following exposure to airborne irritants, which in some cases may result from stimulation of irritant receptors in the upper airways inducing reflexive bronchoconstriction. Ammonia (NH3) is a common constituent of commercially available household products, and in high concentration has the potential to elicit sensory irritation in the eyes and upper respiratory tract of humans. The goal of the present study was to evaluate the irritation potential of ammonia in asthmatics and healthy volunteers and to determine whether differences in nasal or ocular irritant sensitivity to ammonia between these two groups could account for the exacerbation of symptoms reported by asthmatics following exposure to an irritant. Twenty-five healthy and 15 mild/moderate persistent asthmatic volunteers, with reported sensitivity to household cleaning products, were evaluated for their sensitivity to the ocular and nasal irritancy of NH3. Lung function was evaluated at baseline and multiple time points following exposure. Irritation thresholds did not differ between asthmatics and healthy controls, nor did ratings of odor intensity, annoyance, and irritancy following exposure to NH3 concentrations at and above the irritant threshold for longer periods of time (30 s). Importantly, no changes in lung function occurred following exposure to NH3 for any individuals in either group. Thus, despite heightened symptom reports to environmental irritants among asthmatics, the ocular and nasal trigeminal system of mild to moderate asthmatics does not appear to be more sensitive or more reactive than that of nonasthmatics, nor does short-duration exposure to ammonia at irritant levels induce changes in lung function. At least in brief exposures, the basis for some asthmatics to experience adverse responses to volatile compounds in everyday life may arise from factors other than trigeminally mediated reflexes.

Neuronal Markers in Allergic Rhinitis: Expression and Correlation With Sensory Testing

Although the role of immunoglobulin E-mediated hypersensitivity reactions in allergic rhinitis is well known, the relative contribution of sensory nerves to the symptoms of rhinitis is uncertain. This study looked at the level of specific neuronal markers including the nerve marker protein gene product 9.5 (PGP 9.5), sensory and autonomic neuropeptides, the capsaicin/heat receptor TRPV1, and nerve growth factor (NGF) in patients with allergic rhinitis and controls and their correlation with nasal sensitivity. Forty patients (23 controls, 17 rhinitis) having nasal surgery were recruited. Nasal sensitivity was tested using graded monofilaments. Inferior turbinate biopsies were collected and studied using immunohistology, with measurement of nerve fibers by direct observation or computerized image analysis. Nerve fibers (PGP 9.5) in the epithelium, subepithelium, and glandular/vascular regions were significantly increased in allergic rhinitis (P=.037, <.01, and .04, respectively), as were subepithelial and glandular/vascular fibers immunoreactive for neuropeptide substance P (P=.04 subepithelium; .02 glandular/vascular) and neuropeptide tyrosine (P<.01 glandular/vascular), markers for sensory and sympathetic nerves, respectively. TRPV1 epithelial fiber counts were higher in rhinitis, but this was not statistically significant. Epithelial NGF immunoreactivity (% area) was significantly increased in rhinitis (P=.027). Nasal sensitivity was correlated significantly with PGP 9.5 subepithelial innervation (control touch P=.023, irritation P=.046; rhinitis touch P=.042, irritation P=.043). A correlation was also observed between epithelial NGF and subepithelial PGP 9.5 innervation, which included all subjects (P=.044). The increased number and specific phenotypical changes of sensory nerves may play a role in nasal hypersensitivity and provide new targets for the treatment of rhinitis.