Neutral endopeptidase activity and concentration of sensory neuropeptide in the human nasal mucosa

Postnasal Drip

Postnasal drip (PND) is a common symptom encountered when evaluating subjects with sinonasal disease; it may be present without sinonasal disease or as a symptom of laryngopharyngeal reflux. It is postulated that PND stems from dysfunction of normal mucus clearance mechanisms; however, there is no definitive evidence elucidating an exact pathophysiology. Compounding the uncertainties surrounding PND is the lack of an objective assessment tool. Instead, treating physicians must rely on subjective complaints and investigators utilize validated patient-reported outcome instruments, such as the Sino-Nasal Outcome Test, to determine treatment efficacy. This review seeks to discuss the current understanding of PND and evidence regarding effective treatment strategies.

Nonallergic Rhinopathy: A Comprehensive Review of Classification, Diagnosis, and Treatment

Chronic nonallergic rhinitis syndromes encompass various conditions, of which vasomotor rhinitis is the most common form, representing approximately 80% of patients, also referred to as nonallergic rhinopathy (NAR), nasal hyperreactivity, neurogenic rhinitis, or idiopathic rhinitis. Expert panels have recommended replacing vasomotor rhinitis terminology because it is more descriptive of this condition that is characterized by symptoms triggered by chemical irritants and weather changes through chemosensors, mechanosensors, thermosensors, and/or osmosensors activated through different transient receptor potential calcium ion channels. Elucidating the specific role of transient receptor potential vanilloid 1, triggered by capsaicin, has been an important advancement in better understanding the pathophysiology of NAR because it has now been shown that downregulation of transient receptor potential vanilloid 1 receptors by several therapeutic compounds provides symptomatic relief for this condition. The classification of NAR is further complicated by its association with allergic rhinitis referred to as mixed rhinitis, which involves both immunoglobulin E-mediated and neurogenic mechanistic pathways. Comorbidities associated with NAR, including rhinosinusitis, headaches, asthma, chronic cough, and sleep disturbances, underscore the need for comprehensive management. Treatment options for NAR include environmental interventions, pharmacotherapy, and in refractory cases, surgical options, emphasizing the need for a tailored approach for each patient. Thus, it is extremely important to accurately diagnose NAR because inappropriate therapies lead to poor clinical outcomes and unnecessary health care and economic burdens for these patients. This review provides a comprehensive overview of NAR subtypes, focusing on classification, diagnosis, and treatment approaches for NAR.

The airway neuro-immune axis as a therapeutic target in allergic airway diseases

Recent evidence has increasingly underscored the importance of the neuro-immune axis in mediating allergic airway diseases, such as allergic asthma and allergic rhinitis. The intimate spatial relationship between neurons and immune cells suggests that their interactions play a pivotal role in regulating allergic airway inflammation. Upon direct activation by allergens, neurons and immune cells engage in interactions, during which neurotransmitters and neuropeptides released by neurons modulate immune cell activity. Meanwhile, immune cells release inflammatory mediators such as histamine and cytokines, stimulating neurons and amplifying neuropeptide production, thereby exacerbating allergic inflammation. The dynamic interplay between the nervous and immune systems suggests that targeting the neuro-immune axis in the airway could represent a novel approach to treating allergic airway diseases. This review summarized recent evidence on the nervous system's regulatory mechanisms in immune responses and identified potential therapeutic targets along the peripheral nerve-immune axis for allergic asthma and allergic rhinitis. The findings will provide novel perspectives on the management of allergic airway diseases in the future.

Therapeutic Strategies to Prevent the Recurrence of Nasal Polyps after Surgical Treatment: An Update and In Vitro Study on Growth Inhibition of Fibroblasts

Chronic rhinosinusitis with nasal polyps (CRSwNP) is the most bothersome phenotype of chronic rhinosinusitis, which is typically characterized by a Type 2 inflammatory reaction, comorbidities and high rates of nasal polyp recurrence, causing severe impact on quality of life. Nasal polyp recurrence rates, defined as the number of patients undergoing revision endoscopic sinus surgery, are 20% within a 5 year period after surgery. The cornerstone of CRSwNP management consists of anti-inflammatory treatment with local corticosteroids. We performed a literature review regarding the therapeutic strategies used to prevent nasal polyp recurrence after surgical treatment. Finally, we report an in vitro study evaluating the efficacy of lysine-acetylsalicylic acid and other non-steroidal anti-inflammatory drugs (ketoprofen and diclofenac) on the proliferation of fibroblasts, obtained from nasal polyp tissue samples. Our study demonstrates that diclofenac, even more so than lysine-acetylsalicylic acid, significantly inhibits fibroblast proliferation and could be considered a valid therapeutic strategy in preventing CRSwNP recurrence.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Functional Endoscopic Sinus Surgery of Nasal Polyposis: The Vexing Question of Whether to Resect or Preserve Middle Turbinate

Functional endoscopic sinus surgery is the mainstay of surgical management of nasal polyposis since 1975. The decision between the partial resection and preservation of the middle turbinate (MT) has stirred up considerable debate. Partial MTR permits easy access to the affected paranasal sinuses intraoperatively and postoperatively. However, there may be alteration of nasal function, frontal sinusitis and anosmia. Preservation of middle turbinate is precludes these complications, and allows the MT to serve as a vital anatomical landmark for revision surgery. Therefore, our study compared the outcomes of the two approaches to aid surgeons in deciding the best possible approach. Randomized control trial. 31 patients (60 sides of nasal cavity) with nasal polyposis were divided into two groups. Group I consisted of 30 sides of nasal cavity with middle turbinate resection, while group II consisted of 30 sides of nasal cavity without middle turbinate resection. Both the groups were compared postoperatively for 6 months. In group I and group II, 5 sides (16.6%) and 11 sides (36.6%) showed polypoidal changes respectively. 3 sides (10%) in group I and 8 sides (26.6%) in group II showed blockage of maxillary sinus ostia. All the sides in group I had patency of frontal sinus. In group II, 5 sides (16.6%) showed blockage of frontal sinus ostia. The maxillary antrostomy patency in group I and group II were 90% (27) and 73.33% (22) respectively. Assessment of symptomatic improvements for nasal obstruction, hyposmia, headache and rhinorrhoea was done using questionnaires. Symptomatic improvement was higher in group I compared to group II with statistical significance (p = 0.001). Our study demonstrated that partial resection of middle turbinate decreased the chances of recurrence of disease and post-operative complications and resulted in significantly better symptomatic improvements.

Clinical effects of middle turbinate resection after endoscopic sinus surgery: a systematic review

BACKGROUND

The middle turbinate (MT) is a structure that is often carefully preserved during endoscopic sinus surgery (ESS) in an effort to preserve nasal physiology and serve as an anatomic landmark. However, resection is performed in select cases because of involvement of the MT in the inflammatory process, obstruction, or instability. Therefore, significant controversy exists among surgeons regarding the indications for proceeding with MT resection in ESS. This study evaluates clinical outcomes of MT resection after ESS.

METHODS

An English language search of the PubMed and Ovid databases was conducted for publications examining clinical outcomes of MT resection after ESS performed for chronic rhinosinusitis. Two authors independently examined the articles to identify those meeting inclusion criteria. Any differences over which studies to include were resolved by discussion and consensus. Bias assessment was conducted using the Cochrane Collaboration bias tool for randomized controlled trials and the Newcastle-Ottawa bias tool for cohort and case-control studies.

RESULTS

After initial screening, search results revealed 71 articles that warranted detailed evaluation. After applying inclusion criteria, 9 studies were selected. A total of 2123 patients were included among the studies. All studies were controlled. Within the limited available data, olfaction scores may be improved in the MT resection patients compared with MT preservation patients. No difference between the groups was noted for quality of life outcomes, nasal airway resistance, or rates of postoperative frontal sinusitis. In regard to postoperative endoscopic examinations, some studies note greater improvement in the MT resection group compared with the MT preservation group, while others were equivalent.

CONCLUSION

Although some studies show outcome benefit in MT resection patients compared with MT preservation patients, several others show no difference. When MT resection was appropriately indicated, no studies showed detrimental effects compared with MT preservation in their designated outcomes. Additional more stringent studies are warranted.

[Local (exclusive) IgE production in the nasal mucosa. Evidence for local allergic rhinitis]

BACKGROUND

IgE production at the site of the nasal mucosa without systemic allergic sensitization in skin tests or in serum represents so-called "local allergic rhinitis (LAR)" as a subgroup of patients with symptoms of allergic rhinitis (AR). Formerly, in case of negative allergological test results, seasonal (intermittent) or perennial (persistent) allergic symptoms have been diagnosed as "non-allergic rhinitis" (NAR). However, there is evidence for specific Th2 cytokine, tryptase, and ECP (eosinophil catonic protein) production in the nasal secretion after allergen exposure in these patients without systemic sensitization.

DIAGNOSIS

Taking this into account, we recommend performing an allergen-specific nasal challenge and measuring the (local) nasal IgE-levels in addition to standard allergy tests in clinical routine in this subgroup of patients. These tests should be perfomed while or shortly after allergen exposure. In addition, an update of the allergy testing should be performed after a time interval since it has been demonstrated that patients formerly diagnosed with NAR may develop LAR or AR, or patients with LAR may develop AR in the future.

TREATMENT

The pharmacological therapeutic options in LAR are in line with the treatment of AR. If and to what extent this subgroup of AR patients benefit from allergen-specific immunotherapy (SIT) is currently being evaluated in clinical trials.

Inflammatory Cell Patterns in the Nasal Mucosa of Patients with Idiopathic Rhinitis

Background

Nonallergic rhinitis comprises many subgroups of rhinitis (vasomotor rhinitis, nonallergic rhinitis with eosinophilia syndrome, occupational rhinitis, idiopathic rhinitis, etc. in which its main feature is known to be free of allergy. We evaluate the cellular infiltrate of subjects with idiopathic rhinitis and compare them with allergic and control counterparts for detecting underlying pathophysiology.

Methods

Subjects selected from patients admitted to Istanbul University Medical Faculty between 2006 and 2009 were classified into idiopathic rhinitis (n = 16; mean age, 26.5 years), allergic rhinitis (n = 17; mean age, 31.1 years), and the control (n = 25, mean age, 28.8 years) groups. Inferior turbinate specimens were collected using Gerritsma forceps. Skin-prick testing was performed. Immunohistochemical detection was performed using B7 (chymase, clone CC1) and G3 (tryptase, clone AA1) primary antibodies for mast cells, human eosinophil major basic protein (clone BMK-13) for eosinophils, and immunoglobulin E (IgE) Ab-1 for mast and plasma cells in epithelium, superficial, and deep submucosa.

Results

We found significantly higher levels of mast cells within the different sites of nasal mucosa of allergic and idiopathic subjects compared with normal mucosa (p < 0.05). Additionally, a significant increase was observed in IgE+ cells of the patients with allergic and idiopathic rhinitis compared with the controls (p < 0.05 for each) Eosinophils were significantly increased within the epithelium of allergic patients’ mucosa.

Conclusion

We seem to have supportive data about possible mechanisms of “idiopathic rhinitis” that suggests local allergic inflammation. The study results provided important information for further provocation and immunohistochemical studies analyzing the shared mechanism of allergic and idiopathic rhinitis.

Exposure to formaldehyde and its potential human health hazards

A widely used chemical, formaldehyde is normally present in both indoor and outdoor air. The rapid growth of formaldehyde-related industries in the past two decades reflects the result of its increased use in building materials and other commercial sectors. Consequently, formaldehyde is encountered almost every day from large segments of society due to its various sources. Many governments and agencies around the world have thus issued a series of standards to regulate its exposure in homes, office buildings, workshops, public places, and food. In light of the deleterious properties of formaldehyde, this article provides an overview of its market, regulation standards, and human health effects.

Rhinorrhea, cough and fatigue in patients taking sitagliptin

Sitagliptin is a dipeptidyl peptidase-4 (DPP IV, CD26) inhibitor indicated for treatment of Type II diabetes as a second line therapy after metformin. We report fifteen sitagliptin intolerant patients who developed anterior and posterior rhinorrhea, cough, dyspnea, and fatigue. Symptoms typically developed within 1 to 8 weeks of starting, and resolved within 1 week of stopping the drug. Peak expiratory flow rates increased 34% in 8 patients who stopped sitagliptin. Similar changes were found in 4 out of 5 persons who had confirmatory readministration. Chart review identified 17 patients who tolerated sitagliptin and had no symptomatic changes. The sitagliptin intolerant group had higher rates of clinically diagnosed allergic rhinitis (15/15 vs. 6/18; p = 0.00005), Fisher's Exact test) and angiotensin converting enzyme inhibitor - induced cough (6/13 vs. 1/18; p = 0.012). Nasal and inhaled glucocorticoids may control the underlying allergic inflammation and abrogate this new sitagliptin - induced pharmacological syndrome. Potential mucosal and central nervous system mechanisms include disruption of neuropeptides and/or cytokines that rely on DPP IV for activation or inactivation, and T cell dysfunction.

Intranasal Capsicum spray in idiopathic rhinitis: a randomized prospective application regimen trial

CONCLUSION

Local Capsicum oleous nasal spray, 4 microg/puff three times a day for 3 consecutive days, is an efficacious and safe treatment for idiopathic rhinitis (IR). Furthermore, being a natural product, Capsicum oleous nasal spray may be readily available for patients.

OBJECTIVES

To evaluate the efficacy and safety of different therapeutic regimens of Capsicum oleous nasal spray in IR.

PATIENTS AND METHODS

A total of 208 patients affected by IR were enrolled in a randomized placebo-controlled trial. Diagnosis of IR was made on the basis of history of nasal obstruction, sneezing and/or rhinorrhoea and after exclusion of other nasal/paranasal anatomic disorders. IR patients were randomized into four groups (groups A, B, and C) receiving increasing doses of Capsicum (1, 2 or 4 microg/puff, respectively) and one group (group D) treated with placebo. Capsicum oleous nasal spray, one puff per nostril, was instilled three times a day at 30 min intervals for 3 consecutive days. Pre- and post-treatment nasal symptoms were evaluated with a daily record chart.

RESULTS

A significant reduction in the frequency of IR symptom was noticed in group C (4 microg/puff, three times a day for 3 consecutive days) vs controls (p=0.003). No significant difference in side effects was recorded in patients receiving Capsicum therapy with respect to controls.

Local IgE production and positive nasal provocation test in patients with persistent nonallergic rhinitis

BACKGROUND

Allergic rhinitis is an IgE-mediated inflammatory disease of the nasal mucosa, which is usually diagnosed by typical symptoms, positive skin tests, and/or serum specific IgE antibodies to allergens. Despite suggestive symptoms of allergic rhinitis, some patients have a negative diagnostic test for atopy.

OBJECTIVE

To evaluate in the nose the inflammatory response, specific IgE to Dermatophagoides pteronyssinus (DP), and the response to a nasal allergen provocation test with DP (NAPT-DP), in patients with persistent nonallergic rhinitis (PNAR) compared with patients with persistent allergic rhinitis (PAR) and healthy controls.

METHODS

Fifty patients with PNAR, 30 with PAR to DP, and 30 healthy controls were studied by determining the nasal leukocyte-lymphocyte phenotype by flow cytometry (CD16, CD8, CD4, CD33, CD3, and CD45), nasal eosinophil cationic protein (ECP), albumin, total and specific IgE to DP, and NAPT-DP.

RESULTS

The PNAR patients showed a similar leukocyte-lymphocyte phenotype in nasal lavage to the PAR patients and was different to the healthy controls. Within the PNAR group, 54% showed a positive NAPT-DP, with 22% of these having nasal specific IgE to DP.

CONCLUSION

These data support the hypothesis that in persistent nonallergic rhinitis some patients may have local inflammation, nasal IgE production, and a positive response to a nasal allergen provocation test despite no evidence of systemic atopy. Further research is needed to evaluate the influence of other perennial allergens and/or immunologic mechanisms.

CLINICAL IMPLICATIONS

The local production of IgE antibodies without systemic detection is a condition that should be considered in patients with PNAR.

Capsaicin treatment of idiopathic rhinitis: the new panacea?

The management of patients with perennial nonallergic or idiopathic rhinitis is difficult. Diagnosis and treatment are hampered by several factors. First, the diagnosis is made by exclusion of other nasal diseases. As a consequence, idiopathic rhinitis is not defined according to clear-cut criteria. A commonly accepted phenotype of idiopathic rhinitis does not exist. Second, the pathophysiology of idiopathic rhinitis is not yet fully elucidated. In contrast with allergic rhinitis, inflammation does not appear to play an important role in idiopathic rhinitis. Recent studies indicate a neural dysregulation of the nasal mucosa. Additionally, the available therapeutic arsenal comprising both pharmacotherapy and surgery is at best partially efficacious in these patients. The efficacy of repeated capsaicin application has been established in several randomized controlled trials. This treatment modality may be the first step to more specific and better treatment options for patients with idiopathic rhinitis that is unresponsive to standard treatment.

Idiopathic rhinitis, the ongoing quest

The term rhinitis in daily practice is used for nasal dysfunction causing symptoms-like nasal itching, sneezing, rhinorrhea and or nasal blockage. Chronic rhinitis can roughly be classified into allergic, infectious or nonallergic/noninfectious. When allergy, mechanical obstruction and infections have been excluded as the cause of rhinitis, a number of poorly defined nasal conditions of partly unknown aetiology and pathophysiology remain. The differential diagnosis of nonallergic noninfectious rhinitis is extensive. Although the percentage of patients with nonallergic noninfectious rhinitis with a known cause has increased the last decades, still about 50% of the patients with nonallergic noninfectious rhinitis has to be classified as suffering from idiopathic rhinitis (IR), or rather e causa ignota. Specific immunological, clinical and sometimes radiological and functional tests are required to distinguish known causes. Research to the underlying pathophysiology of IR has moved from autonomic neural dysbalans to inflammatory disorders (local allergy), the nonadrenergic noncholinergic (NANC) sensory peptidergic neural system and central neural hyperaesthesia, still without solid ground or proof. This review summarizes the currently known causes for nonallergic noninfectious rhinitis and possible treatments. Also possible pathophysiological mechanisms of IR are discussed.

Intranasal capsaicin reduces nasal hyperreactivity in idiopathic rhinitis: a double-blind randomized application regimen study

BACKGROUND

In a recent study, we showed that intranasal capsaicin spray gives a significant and long-term reduction of symptoms in nonallergic noninfectious perennial rhinitis patients. However, in daily practice, the studied application regimen proved to be impractical because of the large number of visits required in a short period of time. In the present study, we conducted a double-blind double-dummy parallel groups trial to determine whether a more practical capsaicin application schedule is equally effective.

METHODS

Thirty patients were randomized into two different treatment regimens: one group received capsaicin five times on the first day at 1-h intervals. This was followed by a placebo dummy once every second or third day for a total of five treatments 2 weeks after the capsaicin application (group A). The other group (B) received the placebo dummy five times on the first day followed by capsaicin once every second or third day for a total of five treatments 2 weeks after the placebo application.

RESULTS

The visual analogue scale scores for overall nasal symptoms, rhinorrhea and nasal blockage showed significant decrease after the start of treatment in both groups, with a significantly steeper decrease in group A. A significant reduction in cold dry air dose responsiveness was also found up to 9 months after therapy in both groups, reflecting a decrease in nasal hyperreactivity. No significant changes in safety data (smell, blood pressure, heart rate) were found.

CONCLUSIONS

We conclude that intranasal capsaicin seems safe to use and that five treatments of capsaicin on a single day is at least as effective as five treatments of capsaicin in 2 weeks.

Specific N-terminal CGRP fragments mitigate chronic hypoxic pulmonary hypertension in rats

Chronic hypoxic pulmonary hypertension (HPH) is characterized by elevated pulmonary arterial pressure (P(PA)), right ventricular hypertrophy (RVH), pulmonary vascular remodeling, pulmonary edema and polycythemia. Currently, there is no safe and effective treatment for HPH. Calcitonin gene-related peptide (CGRP) is the most potent peptide vasodilator discovered thus far. We previously demonstrated that exogenous CGRP reversed HPH in rats. However, the CGRP1 receptor antagonist CGRP(8-37) and smaller inhibitory C-terminal CGRP fragments that can be formed by enzymatic cleavage in vivo may compromise the beneficial effects of endogenous or exogenous CGRP. We here examine the agonistic efficacy of N-terminal rat alpha-CGRP peptides containing the disulfide bridge (Cys(2)-Cys(7)) with amidated C-terminal in prevention of HPH. Chronic infusion of CGRP(1-8), CGRP(1-13), or CGRP(1-14) at 7 nmol/h/rat via the right jugular vein during 14 days of hypobaric hypoxia (10% inspired O(2)) significantly decreased the P(PA), RVH and pulmonary arterial medial thickness in comparison with controls, suggesting that these CGRP sequences can mitigate chronic HPH in rats. Systemic pressure was unchanged by infused peptides indicating no carry-over effect. In conclusion, N-terminal CGRP fragments (CGRP(1-8), CGRP(1-13) and CGRP(1-14)) may have a protective role in hypoxic pulmonary hypertension.

Loss of dipeptidylpeptidase IV activity in chronic rhinosinusitis contributes to the neurogenic inflammation induced by substance P in the nasal mucosa

In this study, we have found that dipeptidylpeptidase IV (DPPIV) plays in vivo an active role in the modulation of the inflammatory response of chronic rhinosinusitis. Human nasal mucosa expresses DPPIV-like immunoreactivity in submucosal seromucus glands, leukocytes, and endothelial cells of blood vessels. DPPIV enzymatic activity in nasal tissue biopsies taken from patients suffering from chronic rhinosinusitis was correlated inversely with the density of inflammatory cells in the nasal mucosa, and the DPPIV activity rose when chronic rhinosinusitis was treated. By using a pig animal model, we have shown that the intranasal administration of recombinant DPPIV decreased the vasodilatation induced by exogenous substance P (SP), a proinflammatory peptide released by sensory nerves. In contrast, an inhibitor of DPPIV enhanced the vasodilatatory effect at low doses of SP. SP5-11 was 100- to 1000-fold less potent than SP as a vasodilator of the nasal mucosa. The vasodilatatory effect of SP was abolished by a NK1 receptor antagonist. In conclusion, these results suggest a new pathophysiological pathway for rhinitis based on clinical observations in humans, indicating the involvement of an enzyme to modulate non-adrenergic and non-cholinergic substrate that occurred during nasal dysfunctions.

Comparison of functional endonasal sinus surgery with and without partial middle turbinate resection

The aim of endonasal sinus surgery is to ameliorate sinonasal symptoms and to achieve a functional nose. Although the importance of opening the ostiomeatal complex is accepted, the role of middle turbinate surgery remains controversial. Although some surgeons emphasize the importance of maintaining the middle turbinate as a physiological humidifier and anatomic landmark, others resect it without adverse sequelae. To date, there have only been limited reviews published to support either approach. This paper examines 1,106 matched patients who underwent similar functional endonasal sinus surgery with (509 patients) or without (597 patients) middle turbinate surgery. We demonstrate a paucity of complications and the potential outcome benefits of judicious partial middle turbinate resection in some patients with more severe rhinosinusitis.

Effect of intranasal treatment with capsaicin on the recurrence of polyps after polypectomy and ethmoidectomy

The aim of this study was to evaluate the influence of five intranasal applications of capsaicin, performed after endoscopic polypectomy associated with partial middle turbinectomy and anterior ethmoidectomy, on the recurrence of nasal polyps and the intensity of nasal obstruction and rhinorrhea. Fifty-one patients (19 females, 32 males, mean age 43 years) suffering from nasal polyposis for more than 1 year were included in this double blind, randomized, placebo-controlled study. During post-surgical controls, local anaesthesia and vasoconstriction of the middle meatus area were performed in all patients with a cotton pellet soaked with lidocain and adrenaline. In 29 patients, the same type of cotton pellet soaked with capsaicin (3 x 10(-6) mol. dissolved in 70% ethanol) was left into the middle meatus of both nostrils for 20 min. As a control group, 22 patients, matched for age and sex, were treated with the capsaicin vehicle alone (70% ethanol). All patients studied received the intranasal treatment once a week for 5 weeks. Subjective evaluations of nasal airway resistance (NAR) and rhinorrhea were recorded by means of a visual analogue scale. Clinical staging of the nasal polyposis (graded from stage 0 = absence of polyp to stage 3 = polyps occupying the entire nasal cavity) was evaluated by the same ENT specialist (ZW) using a 0 degrees endoscope. All parameters were recorded for each patient 1 week before surgery, then once a month for 9 months. Patients treated by endoscopic surgery followed by intranasal capsaicin application, reported a marked reduction in their NAR compared with the pretreatment evaluation (p<0.001). In contrast, patients treated with the vehicle alone did not have any significant improvement of their subjective NAR. Subjective rhinorrhea was not modified by either treatment. Patients treated with capsaicin showed a significant smaller staging of their nasal polyposis compared with the control group (p<0.001). These observations suggest that endoscopic surgery followed by intranasal capsaicin application reduces polyps and nasal obstruction recurrence and could be an alternative treatment to expensive corticosteroids in developing countries.

Hyperresponsiveness in the human nasal airway: new targets for the treatment of allergic airway disease

Allergic rhinitis is a condition which affects over 15% of the population in the United Kingdom. The pathological process involves two stages: nasal inflammation, and the development of nasal airway hyperresponsiveness (AHR) to allergen and a number of other stimuli. This results in the amplification of any subsequent allergic reaction, contributing to the chronic allergic state. A number of different hypotheses have been proposed to explain the underlying mechanism of AHR, including a role for eosinophil-derived proteins, free radicals and neuropeptides. While there may be a number of independent pathways which can result in AHR, evidence obtained from both animal models and in vivo experiments in humans indicate that some mediators may interact with one another, resulting in AHR. Further research into these interactions may open new avenues for the pharmacological treatment of chronic allergic rhinitis, and possibly other allergic airway diseases.

Intranasal administration of neuropeptide Y in man: systemic absorption and functional effects

1. Exogenous neuropeptide Y (NPY, 10 nmol, 50 nmol and 100 nmol) and its vehicle (NaCl 0.9%) were administered in a double blind, randomized and controlled manner by intranasal spray in 7 healthy volunteers. Variations of plasma NPY concentration over time were measured during 120 min. Forty min after the administration of 50 nmol and 100 nmol of exogenous NPY, plasma NPY increased from 5.5 +/- 1.1 pM to 9.8 +/- 2.3 pM (P < 0.05) and from 9.06 +/- 5.1 pM to 20.8 +/- 6.16 pM (P < 0.001), respectively. There was no significant modification of the mean arterial blood pressure and no subjective discomfort was reported. 2. Nasal airway resistance (NAR) was measured by anterior rhinomanometry and was reduced by 25 +/- 3% and 32 +/- 5% after the spray of 50 nmol and 100 nmol, respectively, for about 90 min. 3. Double-blind, randomized, placebo-controlled and 3-way crossover design experiments were performed in 8 healthy volunteers to evaluate the influence of intranasal pretreatment with NPY (20 nmol) and the mixed alpha 1/alpha 2-adrenoceptor agonist oxymetazoline (20 nmol) on the functional effects of subsequent local irritation evoked by capsaicin (3.3 x 10(-4) mol). Subjective evaluation of NAR and local intensity of discomfort were evaluated by means of a visual analogue scale. Nasal secretions were collected and objective NAR was recorded by rhinomanometry. 4. Subjective NAR, nasal secretions and rhinomanometry recordings were not modified by intranasal application of saline, NPY or oxymetazoline. Subjective nasal obstruction, local discomfort, nasal secretions and NAR increase evoked by capsaicin were markedly reduced by NPY pretreatment (P < 0.05) when compared to saline or oxymetazoline. 5. It is concluded that intranasal application of exogenous NPY has very low systemic absorption but induced long lasting nasal vasoconstriction without cardiovascular effects. Pretreatment of the nasal mucosa with exogenous NPY reduces both secretagogue and vasodilator responses to subsequent application of capsaicin.