Increased expression of major basic protein (MBP) and interleukin-5(IL-5) in middle ear biopsy specimens from atopic patients with persistent otitis media with effusion

Allergy in pathogenesis of Eustachian Tube Dysfunction

Eustachian tube dysfunction (ETD) is a condition where the Eustachian tube (ET) fails to function normally, resulting in symptoms such as aural fullness, tinnitus, autophony, and hearing loss. ETD can further lead to middle ear diseases such as otitis media effusion and adhesive otitis media, which is becoming more common in the field of otology. Although the pathogenesis of ETD remains unclear, recent animal studies and clinical experiments have found allergic reactions and allergic diseases are closely related to the occurrence of ETD. As the mucosa of the ET is continuous with that of the nasopharynx and tympanic cavity, it is reasonable to assume that the immunological basis of the ET itself is similar to that of respiratory allergic diseases. However, due to the special anatomical location and complex pathogenesis of the ET, there is still no unified diagnostic gold standard. Additionally, there is an ongoing debate regarding whether ETD can be classified as a distinct disease or even an allergic disease. Furthermore, the effectiveness of anti-allergic therapy in patients with ETD is yet to be fully understood. Therefore, this review elaborates on the possible mechanisms of allergic reactions in the occurrence and development of ETD, and explores the potential role of anti-allergic therapy in managing this condition, in order to provide new insights into the pathogenesis and prevention of ETD.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Otitis media in children: Which phenotypes are most linked to allergy? A systematic review

BACKGROUND

Allergic rhinitis is a common childhood disease responsible for a major impact on quality of life and healthcare resources. Many hypotheses have been proposed to explain the link between allergy and otitis media, although a definitive mechanism has not been identified yet. One of the major critical points is that authors failed in distinguishing among different phenotypes of middle ear inflammation. This review pointed out literature evidence from the laboratory and clinical experience linking allergy to different phenotypes of otitis media in children.

METHODS

We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) process. Our search yielded 3010 articles that were finally screened. This resulted in 20 manuscripts of which the full texts were included in a qualitative analysis. We paid particular attention in distinguishing among phenotypes of otitis media.

RESULTS

Clinical evidence and analyses of biomarkers suggested that allergy may be linked to some phenotypes of otitis media and, in particular, to otitis media with effusion (OME) and acute re-exacerbations in children with middle ear effusion. It was not possible to perform the analysis for allergy and acute and chronic otitis media because of paucity and heterogeneity of data.

CONCLUSION

Allergy should be considered in the diagnostic workup of children with OME as well as OME should be excluded in children with persistent moderate to severe AR. In these cases, clinicians should evaluate prompt and accurate treatment of allergy in improving outcomes, although futures studies are required to increase evidence supporting that anti-allergy treatment may be effective in the recovery and outcome of otitis media with effusion.

Effects of allergic rhinitis on the progression and recovery of acute otitis media in a mouse model

OBJECTIVES

The objective of this study was to evaluate the effects of allergic rhinitis (AR) on the development, progression, and recovery of acute otitis media (OM) in an animal model and investigate the secondary effects of bacterial infection.

METHODS

BALB/c mice were divided into four groups: AR + OM, AR, OM, and control groups. AR + OM and AR groups were sensitized with ovalbumin (OVA) and alum and then challenged intranasally with OVA. Phosphate-buffered saline (PBS) was administered to the OM and control groups the same number of times. After AR induction, OM was induced by surgical inoculation of non-typeable Haemophilus influenza (NTHi) into the middle ear (ME) cavity of the mice in the AR + OM and OM groups. PBS was injected into the bulla in the AR and control groups. Each group was subdivided into sets of six mice, one for each of the four time points (0, 2, 7, and 10 days post-bacterial inoculation), at which point the mice were euthanized and ME and nasal cavity mucosa were obtained and evaluated. The occurrence of OM and the ME mucosa thickness were evaluated and compared among the four groups. Tissue expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in infected ME mucosa was assessed by immunohistochemical staining. We also investigated IgE, IL-4, and IL-5 in the nasal mucosa.

RESULTS

Most of the ears showed OM on post-inoculation day 2 in both AR + OM and OM groups. In the AR + OM group, 58.3% of ears still had OM on post-inoculation day 10, while only 16.7% of the OM group had OM. The ME mucosa of all groups increased, and the AR + OM group exhibited the thickest mucosa. The OM group showed peak thickness on post-inoculation day 2 and then decreased, whereas the ME mucosa thickness of the AR + OM group continued to increase to day 7. In the OM group, the expression of IL-1β, IL-6, and TNF-α in the ME also increased significantly, peaking on post-inoculation day 2, and then gradually decreased. In the AR + OM group, the expression of these proteins increased until day 7 and then decreased. The IgE and Th2 response (IL-4 and IL-5) cytokines were expressed at higher levels in the AR + OM and AR groups than in the OM and control groups.

CONCLUSION

The inflammatory reaction to NTHi was more intense and lasted longer in the allergic group, which indicates that AR affects the progression and subsequent recovery of acute bacterial OM.

The Relation of Allergy to Eustachian Tube Dysfunction and the Subsequent Need for Insertion of Pressure Equalization Tubes

INTRODUCTION

The most basic question to be answered in each case in which the choice of using a pressure equalization tube (PET) is being considered is: "what is the underlying pathophysiology of the middle ear disease being addressed?"

METHODS

We will evaluate the hypothesis that the Eustachian Tube (ET) may become "dysfunctional" due to allergic mucosal edema and obstruction. We review the literature that evaluates the role of ET, the proposed affect that allergy may contribute to ET dysfunction (ETD), and the relation of allergic rhinitis to otitis.

RESULTS

Proof that allergy affects the middle ear was supported by (1) over a dozen investigators using objective immunotherapy demonstrating over the past 70 years that 72% to 100% of the children with otitis media with effusion (OME) are atopic, (2) an association of allergic Th2 immune-mediated histochemical reactivity within the target organ itself, (3) establishment that inflammation within the middle ear is truly allergic in nature, and (4) direct evidence of a dose-response curve and consistency of results, which confirm that OME resolves on allergy immunotherapy.

CONCLUSION

Current medical evidence should heighten the awareness of physicians of the physiology that underlies ETD. The evidence supports the link between allergy and OME. The middle ear behaves like the rest of the respiratory tract, and what has been learned about the atopic response in the sinuses and lungs may be applied to the study of the immunologic mechanisms within the middle ear that lead to ETD requiring the use of PET.

Vitamin D and Otitis Media

PURPOSE OF REVIEW

To examine the relationship between vitamin D and otitis media.

RECENT FINDINGS

Vitamin D deficiency has been associated with several respiratory diseases, including otitis media. Vitamin D supplementation may reduce the risk of otitis media. This relationship may be explained by vitamin D supporting the immune system by upregulating antimicrobial peptides which are effective against otopathogens and biofilm formation, supporting a less inflammatory immune response, or promoting beneficial commensal bacteria. This review will explore risk factors of both otitis media and vitamin D deficiency, the evidence of vitamin D being beneficial for various forms of otitis media, and possible mechanisms of action.

[The modern approaches to the evaluation of the importance of chronic inflammation in the mucous membrane of the middle ear]

Despite the ever growing progress in antibiotic therapy and the advent of the new methods for this purpose, the number of patients suffering from chronic focal infection of the ENT organs has not decreased during the last decades which turns the problem of chronization of inflammation into a serious challenge for the physicians as exemplified by chronic inflammation in the mucous membrane of the middle ear. Pathological changes in the middle ear make up a large fraction of ENT diseases of importance not only for otorhinolaryngologists but also for the specialists in the related medical disciplines. The present article is an overview of etiological, pathogenetic, and pathomorphological aspects of chronization of the inflammation process that are known to occur in the mucous membrane of the middle ear. In the overwhelming majority of the cases, the main cause of the conversion of acute inflammation in the middle ear into the chronic condition is the inadequate (incorrect), inopportune or incomplete treatment of the acute inflammatory process in the middle ear.

Allergy genuflection? It's surmount with special focus on ear, nose and throat

The system that protects body from infectious agents is immune system. On occasions, the system seldom reacts with some foreign particles and causes allergy. Allergies of the ear, nose and throat (ENT) often have serious consequences, including impairment and emotional strain that lowers the quality of life of patients. This is further responsible for the common cold, cough, tonsillitis, dermal infection, chest pain and asthma-like conditions which disturb one's day to day life. The present review enlightens some common ENT allergies which one can suffer more frequently in one's lifetime, and ignorance leads to making the condition chronic. Information regarding pathophysiology and the management of ENT allergy by this review could help clinicians and common people to better understand the circumstances and treatment of ENT allergy.

The Role of Allergy in Otologic Disease

Allergy is commonly associated with conditions such as rhinitis, sinusitis, and asthma, but the relationship between allergy and otologic diseases is less clear. This article examines the evidence for a relationship between allergic disease and several common otologic conditions, including otitis media with effusion, eosinophilic otitis media, and Ménière's disease.

What Role Does Allergy Play in Chronic Ear Disease and Laryngitis?

IgE-mediated allergy plays a well-established role in both nasal and pulmonary diseases due to the common epithelium and shared mediator responses of the upper and lower airways. This "unified airway" concept has also been described in other sites within the head and neck that contain similar respiratory mucosa: the middle ear and the larynx. This review will highlight the data suggesting a role for IgE-mediated allergic disease in chronic laryngopharyngeal and middle ear disease and the role for allergy testing to aid in diagnosis and treatment of these disorders.

Synergistic Effect of Dermatophagoides farinae and Lipopolysaccharides in Human Middle ear Epithelial Cells

Purpose

Although the concept of "one airway, one disease," which includes the middle ear space as part of the united airway is well recognized, the role of allergens in otitis media with effusion (OME) is not clearly understood. We aimed to investigate the effect of the interaction between Dermatophagoides farinae (Der f) and lipopolysaccharide (LPS) on the induction of epithelial inflammatory response in vitro.

Methods

Primary human middle ear epithelial cells were exposed to Der f, LPS, or both in different sequences, and the magnitude of the immunologic responses was compared. The mRNA expressiona of mucin (MUC) 4, 5AC, 5B, 8, GM-CSF, TNF-α, TLR4, and MD-2 were evaluated using real-time PCR. MUC levels before and after siRNA-mediated knockout of TLR4 and MD-2 were assessed. Lastly, the involved cell signaling pathway was evaluated.

Results

The expressiona of cytokines, and the MUC 4, 5AC, 5B, and 8 genes were augmented by pretreatment with Der f followed by LPS; however, reverse treatment or combined treatment did not induce the same magnitude of response. Increased MUC expression was decreased by TLR4 knockdown, but not by MD-2 knockdown. The signal intensity of MUC 8 was higher in MD-2 over-expressed cells than in those exposed to LPS only. The translocation of nuclear factor-κB was observed in cells pretreated with Der f followed by LPS.

Conclusions

When Der f treatment preceded LPS exposure, Der f and LPS acted synergistically in the induction of pro-inflammatory cytokines and the MUC gene, suggesting an important role in the development of OME in patients with concealed allergy airway sensitization.

Otitis media with effusion in an allergic animal model: A functional and morphological study

OBJECTIVES

Allergy is considered as one of important etiologic factor of otitis media with effusion (OME). In present study, we evaluated the causal effect of allergy on OME in an animal model, and investigated the secondary effect of bacterial infection.

METHODS

Allergy and control animals were subdivided into groups with and without intratympanic injection of lipopolysaccharide (IT-LPS). Allergic otitis media was induced via intraperitoneal ovo-albumin injection with intranasal challenge. We assessed the occurrence of OME in allergic animals and the effect of IT-LPS on allergic otitis media. We also investigated the Th1 and Th2 responses in the middle-ear mucosa. Hearing of the animals was measured by ABR and DPOAE.

RESULTS

OME was observed in 75% of the allergic animals. After IT-LPS, 100% of the control and allergy groups showed otitis media. Light microscopy revealed that the middle-ear mucosa of animals of both groups also was significantly increased after IT-LPS, and the Th1 response (IL-2 and IFN-γ) and Th2 response (IL-5 and IL-13) cytokines were expressed at higher levels in the allergy group with IT-LPS than in control group with IT-LPS. Hearing tests between the allergy and control group with IT-LPS did not reveal any differences.

CONCLUSION

Our findings may be direct evidence of an allergic causal effect on OME. Th2 response cytokines were strongly expressed in allergic OME, and the inflammatory reaction to LPS was more intense in the allergic group, which indicates that otitis media related to allergy can be severely aggravated by an inflammatory reaction to bacterial infection.

Prevalence of otitis media with effusion in children with allergic rhinitis, a cross sectional study

OBJECTIVES

Otitis media with effusion (OME) may be caused by various factors including Eustachian tube dysfunction, inflammatory response as well as atopy. Allergic rhinitis (AR), a common chronic disorder in children, is associated with swelling of the mucosa and can therefore result in Eustachian tube dysfunction. This study aims to compare the prevalence of OME in subjects with and without AR.

METHOD

Children aged 4-12 were recruited from the clinics at Kwong Wah Hospital, Hong Kong. Subjects recruited were interviewed and a questionnaire filled in regarding nasal obstruction, rhinorrhea, sneezing, itching of the nose and/or post nasal discharge (ARIR document). The children were then examined by a doctor using a pneumatic otoscopy and a portable tympanometer. Children found to have OME were offered a follow-up visit 3 months later.

RESULTS

12 out of 159 (7.5%) of the AR group were found to have OME compared with 3 out of 185 (1.6%) in the non-AR group, p=0.016. During the 2nd visit at 3 months, 85.7% of the AR subjects showed resolution of their OME.

CONCLUSIONS

Our data showed a significant difference in the prevalence of OME between AR and non-AR subjects. Of the 185 non AR subjects (Control group), 3 was found to have OME, suggesting a point prevalence of OME of 1.6% in the community in Hong Kong. OME is more likely to occur in children with allergic rhinitis and it may be wiser to manage OME in these individuals differently.

Sinus and adenoid inflammation in children with chronic rhinosinusitis and asthma

BACKGROUND

Chronic rhinosinusitis (CRS) and asthma frequently coexist in children and adults. However, the precise pathophysiologic mechanism of this interaction is still poorly understood, especially in children, owing to the lack of direct measurements of mucosal inflammation in the upper airways.

OBJECTIVE

To determine the pathophysiologic mechanism by analyzing the expression of a large array of inflammatory cytokines and chemokines in the sinus and adenoid tissues surgically removed from pediatric patients with CRS refractory to medical management.

METHODS

Twenty-eight children 2 to 12 years old diagnosed with CRS with or without asthma and 10 controls were included in this prospective, nonrandomized study. Mucosal expression of 40 inflammatory cytokines was measured with a multiplex assay and was normalized to total tissue protein.

RESULTS

Compared with children with CRS and without asthma, children with CRS and asthma had significantly higher sinus levels of tumor necrosis factor-α and adenoid levels of epidermal growth factor, eotaxin, fibroblast growth factor-2, growth-related oncogene, and platelet-derived growth factor-AA.

CONCLUSION

The inflammatory response in the upper airway mucosa of children with asthma and CRS was similar, but more severe, compared with children with CRS without asthma. This observation is consistent with the hypothesis that asthma in these patients is caused or exacerbated by severe upper airway disease and supports the concept that treating sinus disease is paramount in the management of chronic asthma in children using, for the first time, direct measurements of airway inflammation in children.

Otitis media with effusion: an effort to understand and clarify the uncertainties

Otitis media with effusion--defined as the accumulation of middle-ear effusion behind an intact tympanic membrane without signs or symptoms of acute infection--is one of the most common causes of hearing loss in children in developed countries, potentially leading to language deficits. Although treatment of chronic or relapsing otitis media with effusion is considered imperative, none of the preventative or nonsurgical management measures currently available have proven effective. Tympanostomy tube placement remains the recommended treatment option for high-risk children or for cases of unresponsive otitis media with effusion. This can be attributed to the uncertainties surrounding its pathogenesis. Multiple factors and several possible pathogenetic models have been proposed to explain the production and persistence of middle-ear effusion; only a few of them are supported by sufficient evidence. In this review, the authors will present current knowledge on the pathogenesis, consequences, diagnosis and management of otitis media with effusion. An effort will be made to clarify those aspects sufficiently supported by evidence-based studies, and to underline those that remain unfounded.

Compensation of cATSCs-derived TGFβ1 and IL10 expressions was effectively modulated atopic dermatitis

In this study, we found an effective and novel therapeutic approach to atopic dermatitis (AD) therapy via treatment with a canine adipose tissue stem cell (cATSC) extract. We determined that the therapeutic application of cATSC-derived interleukin 10 (IL10) and transforming growth factor β1 (TGFβ1) effectively modulated the overloaded immune response after the induction of AD. In addition, we investigated the molecular role of the cATSC extract during AD treatment. Dogs with naturally occurring AD that was treated at Seoul National University Veterinary Teaching Hospital was enrolled in this study. Owner consent was obtained for privately owned dogs before enrollment. We prepared a primary fat-derived cATSC extract that contained various functional factors, including IL10 and TGFβ1, as a treatment for AD. We found that the cATSC extract significantly ameliorated the pathological symptoms of canine AD. The cATSC extract secreted the immunomodulatory cytokines IL10 and TGFβ1, which modulated the overloaded immune response after the induction of AD. Moreover, these immunomodulatory cytokines modulated AD-induced inflammation and inactivated the pathological signals IL6, INFγ, iNOS, eNOS and Nox4. Additionally, these cytokines protected against apoptotic keratinocyte degeneration. This study demonstrated the novel therapeutic efficacy of the cATSC extract during successive AD treatments, which suggests a potential therapeutic use for human AD patients.

Is there an association between otitis media and nasal polyposis?

The association between otitis media with effusion (OME) and nasal polyposis (NP) is poorly described. However, two different approaches to this problem seem to come from the few studies concerning both otitis media and NP in the literature. One study was based on the assessment of a population of patients presenting with NP, with the authors interested in patients among the studied population who complained of ear-related symptoms and developed OME (rhinologic approach). Other studies were based on the assessment of a population of patients developing a particular OME, with the authors interested in characterizing this condition they named eosinophilic otitis media (otologic approach). The article reviews currents concepts in the relationship between OME and NP. It appears that regardless of the approach to the problem of interest (rhinologic or otologic approach), OME and NP seem to be closely related. Moreover, some striking similarities can be noted between the different entities described in the different studies reviewed, and all authors seem to agree that the middle ear has a central role in the concept of united airways inflammatory disease. Otologists and rhinologists should work together on a single approach that allows for better management of inflammatory disease leading to the formation of polyps, development of concurrent asthma, appearance of aspirin intolerance, and finally involvement of the middle ear.

Audiological investigation of otitis media in children with atopy

Otitis media (OM) describes an inflammatory process within the middle ear space that is generally associated with accumulation of fluid and that may lead to hearing loss, learning difficulties, and delays in language development. The pathogenesis of OM is multifactorial, involving the adaptive and native immune system, eustachian tube dysfunction, viral and bacterial load, and genetic and environmental factors. The involvement of IgE-mediated allergic reactions in the pathogenesis of OM has been suggested by clinical observations of a high prevalence of OM among patients with allergies. Evidence from studies involving tympanometric measurements, audiometric measurements, and otoscopic examination confirms the role of atopy in the development and persistence of OM.

The role of allergy in otitis media with effusion

The role of allergy in chronic otitis media with effusion (OME) is controversial. New evidence from cellular biology and immunology explain the basics of allergic reactions and allow more accurate diagnosis of allergies and inflammatory disease throughout the unified airway. This article examines the epidemiologic, methodological, and immunologic studies of allergic causes of OME, including (1) evidence for and against OME as an allergic disease, (2) allergy as a cause for eustachian tube obstruction, (3) examination of the most sensitive diagnostic tests for allergy, and (4) the effect of treatment of underlying allergies in improving and resolving middle ear disease.

Otitis media and antihistamines

Otitis media with effusion (OME) and acute otitis media (AOM) continue to be a significant source of morbidity in the United States, as they account for more than 3.5 billion dollars in annual costs, and OME is the sixth most common reason for an emergency department visit. The efficacy of antihistamines in the treatment of OME/AOM has been thoroughly refuted in the literature during the past three decades. However, most studies to date have used first-generation antihistamines with or without decongestants. We propose that second-generation antihistamines may have increased efficacy in the treatment of OME/AOM because of their greater selectivity for histamine receptors and lack of anticholinergic activity. Further clinical trials may be warranted, as medical treatment with second-generation antihistamines, if proven more efficacious, may reduce the need for antibiotic treatment and surgical intervention.

Atopy: pediatric ENT manifestations in children

OBJECTIVE

The aim of the present study is to discuss the basics of atopy in children in relationship to the principal ENT allergic disorders such as allergic rhinitis, rhinosinusitis and their impact on lower airways, allergic otitis media, and oral cavity focusing on their natural history.

METHODS

An updated and exhaustive review of principal literature on these topics is performed, underlining the constant but growing interest evoked by these disorders most of all the possible sequelae or complications. Considering the different districts which can be selectively or simultaneously affected by the allergic sensitisation, diagnosis can be a really hard task; in this paper, we tried to draw an integrated diagnostic approach to atopic children and some guidelines for a correct therapeutic approach.

CONCLUSIONS

Atopic disorders could expose young patients to years of chronic diseases that interferes with their development and with many important aspects of their lives. For these reasons, and considering the high social and medical costs of this disease, it is extremely important to adequately treat allergic pathologies from the early phases of its natural history. Moreover, we cannot forget that an appropriate therapy of allergic pathologies should not be only able to decrease symptoms but, it should also be able to improve patients health related quality of life.

Expression of GATA3, T-bet, IL-4, and IFN-gamma mRNA in the effusion of OME patients

OBJECTIVE

The role of allergy in the pathophysiology of otitis media with effusion (OME) remains unclear. We evaluated the role of allergy and the Th1/Th2 balance in OME patients.

METHOD

Middle ear fluid was collected from 46 OME patients who had a ventilating tube inserted, and expression of GATA3, T-bet, IL-4, and IFN-gamma mRNA was assessed by RT-PCR. Expression of transcription factors and cytokines was compared in patients with and without allergy.

RESULTS

The levels of GATA3 and T-bet mRNA in effusion fluid correlated positively with the levels of IL-4 and IFN-gamma mRNA, respectively. However, the allergy and non-allergy groups showed no significant differences in expression of any of these transcription factors and cytokines. The T-bet:GATA3 ratio was higher in the non-allergy than in the allergy group, but the difference was not statistically significant.

CONCLUSION

Although we observed a significant positive correlation between GATA3 and IL-4 mRNA levels, we cannot conclude that OME with allergy is related to a Th-2 driven immune response.

Poly(I:C) synergizes with Th2 cytokines to induce TARC/CCL17 in middle ear fibroblasts established from mucosa of otitis media with effusion

CONCLUSION

These results suggest that middle ear fibroblasts contribute to the recruitment of Th2 cells into the middle ear by producing thymus and activation-regulated chemokine (TARC).

OBJECTIVES

Intractable otitis media is more common in atopic subjects and asthmatics than in the otherwise normal population. Although type 2 T helper (Th2) cytokines play crucial roles in the middle ear of these populations, the mechanism underlying the predominance of Th2 cytokines has yet to be clarified. TARC has been known to facilitate recruitment of Th2 polarized cells, resulting in high levels of Th2 cytokines in the middle ear. We investigated whether middle ear-derived fibroblasts produce TARC when stimulated with poly(I:C) and Th2 cytokines (IL-4, IL-13).

MATERIALS AND METHODS

Fibroblast lines were established from middle ear mucosa. TARC mRNA expression was evaluated by real-time RT-PCR. The amount of TARC in the culture supernatants was measured by ELISA.

RESULTS

Poly(I:C) induced only TARC gene expression in middle ear-derived fibroblasts. Combined stimulation with poly(I:C) and Th2 cytokine (IL-4, IL-13) synergistically induced TARC production by the cultured middle ear-derived fibroblasts. This response was dose and time dependent.

Role of nasal allergy in chronic secretory otitis media

Nasal allergy seems to be one of the important causes of chronic secretory otitis media (SOM) in children and adults. Chronic SOM is unequivocally related to disturbed function of the eustachian tube, which facilitates communication of the middle ear with the nasopharynx, nasal cavity, and indirectly with paranasal sinuses. The most serious consequences of chronic SOM are decreased elasticity of the tympanic membrane and hearing impairment. Allergic reactions in the nasal mucosa leading to release of various mediators result in development of three types of nasal response characterized predominantly by nasal obstruction. Eustachian tube functions can be affected directly by the mediators released in the nasal mucosa or indirectly by the nasal obstruction. Nasal challenges with allergens performed by rhinomanometry, combined with tympanometry and eventually audiometry, may be a useful diagnostic supplement for this disorder.

Immune modulatory oligonucleotides in the prevention and treatment of allergen-induced eustachian tube dysfunction in the animal model

This article reviews the current literature investigating the applications and success of immune modulatory oligonucleotides as immunotherapy to treat and prevent allergen-induced eustachian tube dysfunction in animal models. Synthetic DNA-based immunotherapy agents composed of unmethylated cytosine-guanine dinucleotides (CpG ODNs) that bind to Toll-like receptors have been found to have tremendous potential as therapeutic agents and adjuvants. CpG ODNs can induce a shift in the cytokine profile and immune response that favors the T-helper type 1 pathway and suppresses the T-helper type 2 pathway. This makes CpG ODNs promising candidates for treating allergic diseases. Current CpG ODN studies have demonstrated prevention and treatment of acute allergen inflammation of the eustachian tube in an animal model of otitis media. Immune modulatory oligonucleotides in immunotherapy, administered systemically or topically, have been shown to be safe and effective in the animal model.

Efficacy of allergy immunotherapy as a treatment for patients with chronic otitis media with effusion

OBJECTIVE

Controversy persists over the significance of allergy as it might relate to chronic middle-ear disease as no controlled study of the efficacy of allergy immunotherapy has been published. The aim of this study was (1) to evaluate the atopic status of patients with intractable chronic otitis media with effusion or drainage from their middle ear and (2) to determine in this select population the efficacy of specific allergy immunotherapy in preventing or limiting the duration of their chronic middle-ear disease.

METHODS

This was a prospective, cohort study of patients cared for in a private community practice. History, examination, audiogram, tympanometry and recurrence of effusion/infection were recorded on 89 patients (52 children <15 years old, 37 adults) referred with (1) effusion found to warrant myringotomy and ventilation tubes, or (2) chronic drainage from a perforation or tube. All were evaluated for allergy by intradermal skin testing according to criteria of the American Academy of Otolaryngic Allergy. A control cohort of 21 patients who refused therapy was included. Intervention consisted of immunotherapy for dust, pollen, and molds. Recurrence or persistence of fluid or drainage following 2-8 years of therapy was compared to the patient's pretreatment status.

RESULTS

All 89 OME patients proved to be atopic. Most were allergic to dust (94%), animals (44%) and molds (88%) while 9% were allergic only to seasonal pollens. Associated allergic diseases included asthma (21%) and allergic rhinitis/sinusitis (63%). Otitis was the sole symptom among 37%. Immunotherapy provided complete resolution of effusion or drainage in 85% of 127 ears.

CONCLUSION

Intradermal testing proved all 89 patients with intractable middle-ear disease in this study who presented with chronic effusion or chronic draining perforations or tubes to be atopic. Specific allergy immunotherapy significantly improved 5.5% and completely resolved 85% of chronic otitis media with effusion in these ears. None of the controls resolved spontaneously (p<0.001). This supports the hypothesis that in many, otitis media with effusion is an immune mediated allergic disease and suggests that these patients deserve consideration for aggressive evaluation and allergy treatment, as most respond to immunotherapy.

The link between allergic rhinitis and chronic otitis media with effusion in atopic patients

The significant incidence of atopy associated with otitis media with effusion (OME) has suggested a role of allergy in the pathogenesis of OME. Analysis of inflammatory mediators indicates that the mucosa of the middle ear can respond to antigen in the same way as does the mucosa of the lower respiratory tract. Recent characterization of the mucosa and effusion from atopic patients with OME reveals a Th2 cytokine and cellular profiles consistent with an allergic response, supporting the role of allergy in OME. In addition, animal studies demonstrate that inhibiting characteristic allergy cytokines can prevent the production of middle ear effusion. As the understanding of allergy and its role in the inflammation of OME continues to deepen, this will introduce focused treatments of OME in the atopic population.

The links between allergy and otitis media with effusion

PURPOSE OF REVIEW

In this review we will examine evidence indicating that allergic inflammation is present in middle ear effusion. We will also discuss several of the problems relating to the diagnosis of allergy and allergic sensitization, and why anti-allergy treatments have been unsuccessful. This will provide a rationale for future studies in the field linking allergic inflammation with otitis media with effusion.

RECENT FINDINGS

Recent findings in atopic children demonstrated higher levels of eosinophils, T lymphocytes, and interleukin-4+ and interleukin-5+ cells compared with nonatopic patients. T-helper 2 cells and cytokines were found not only in middle ear effusions in atopic children but also in specimens from adenoid tissue. This demonstrates a strong correlation between allergic reaction in the middle ear and the upper airway.

SUMMARY

In summary, as our knowledge of the allergic and nonallergic influences on inflammation broadens, the paradigms of treatment may be altered. The accumulating experimental and clinical data suggest that it may be wiser to screen every child with otitis media with effusion for allergic rhinitis and ultimately to manage those with allergic inflammation differently to nonatopic individuals with otitis media with effusion.

Th1/Th2 and Regulatory Cytokines in Adults With Otitis Media With Effusion

OBJECTIVE

Otitis media with effusion is one of the most common and intractable ear diseases. However, the role of Th1, Th2, and immunoregulatory cytokines on the pathogenesis of the disease in adult patients remains to be determined. The aim of this study is to disclose the cytokine expression in middle ear effusions (MEEs) in adults and to compare the profile on the basis of the presence of allergic rhinitis and the type of effusions.

STUDY DESIGN

A prospective controlled clinical study.

PATIENTS

MEEs were collected from 80 adult subjects. The concentration of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, and interferon (IFN)-gamma in MEEs were determined by using enzyme-linked immunosorbent assay.

RESULTS

IL-2, IL-4, IL-5, IL-10, IL-12, and IFN-gamma in MEEs were detected in 60 (75.0%), 33 (41.3%), 42 (52.5%), 14 (17.5%), 80 (100%), and 66 (82.5%) samples, respectively. Among these cytokines, only the concentration of IL-4 in the allergic rhinitis-positive group was significantly higher than that in the allergic rhinitis-negative group. On the other hand, IL-2, IL-12, and IFN-gamma were detected, regardless of the presence of allergic rhinitis, and the concentration of these cytokines correlated with each other. The correlation between the concentration of IL-4 and IL-5 was also detected. In addition, both the incidence rate and the concentration of IL-10 in MEEs were significantly higher in the mucoid type compared with those in the serous type effusions.

CONCLUSION

Regardless of allergic status, IL-12 may play a critical role in the pathogenesis of otitis media with effusion by affecting the production of IL-2 and IFN-gamma. In addition, IL-4 may have some impact on the immunologic condition in adults with allergic rhinitis. IL-10 potentially affects the viscosity of MEEs.

The role of immunomodulatory oligonucleotides in prevention of OVA-induced Eustachian tube dysfunction

OBJECTIVE

To evaluate the potential role of immunomodulatory oligonucleotides (IMO) in the prevention of OVA-induced Eustachian tube dysfunction (ETD) in a rat model.

METHODS

Brown-Norway rats were sensitized to ovalbumin (OVA) and randomized to receive pre-treatment with IMO or phosphate buffered saline (PBS). After systemic sensitization, subjects received a transtympanic OVA challenge followed by evaluation of the Eustachian tube's dynamic function.

RESULTS

Pre-treatment of OVA sensitized animals with IMO normalized passive opening and closing Eustachian tube pressures, improved active clearance of negative pressure in the middle ear, and resulted in reduced mean mucociliary transit times compared to untreated OVA-sensitized animals (P<0.001).

CONCLUSION

These data demonstrate that pre-treatment with IMO prevent OVA-induced ETD in the rat. IMO treatment in the future may offer considerable promise in the management of OME in children.

Expression of matrix metalloproteinase-9 and -2 in pediatric chronic otitis media with effusion

OBJECTIVE

To evaluate the role of MMP-9 and MMP-2 in pediatric patients with middle ear effusion (MEE) and determine the pathogenesis of otitis media with effusion (OME) and allergy.

METHODS

The MEE samples were collected from 25 patients with allergy and 20 patients without allergy as a control. The levels of MMP-9 and MMP-2 were measured using a commercially available enzyme-linked immunosorbent assay (ELISA). The activity of MMP-9 and MMP-2 were measured by gelatin-zymography. The Mann-Whitney U-test was used for comparisons between the allergy positive and control groups.

RESULTS

The level of MMP-9 was significantly elevated in MEE from the allergy positive group compared to controls. The amount of MMP-9 activity significantly increased in the allergy positive group compared to controls.

CONCLUSION

MMP-9 and MMP-2 are mediators of inflammation in the OME; in addition, MMP-9 may play a significant role in the pathophysiology of OME with allergy.

Allergic rhinitis and its impact on otorhinolaryngology

Allergic rhinitis (AR) is a disease with growing impact on everyday medical practice, as its prevalence has steadily increased during the last decades. Immunoglobulin-E (IgE)-mediated airway inflammation may manifest itself as AR, asthma or both. Allergic inflammation in upper and lower airways is now considered as one airway disease, with manifestation of symptoms in upper, lower or global airway. This insight into allergic inflammation of the whole respiratory tract has consequences for the diagnostic and therapeutic approach of affected patients, as highlighted in the ARIA document. In contrast to asthma, the link between AR and associated conditions in the upper airways like rhinosinusitis, nasal polyps, recurrent viral infections, adenoid hypertrophy, tubal dysfunction, otitis media with effusion and laryngitis remains less explored. It is however of utmost importance to consider the aetiological role of IgE-mediated inflammation of the nasal mucosa in several diseases of the upper respiratory tract, as they represent a large body of patient population seen by the general practitioner as well as the paediatrician, allergologist and otorhinolaryngologist. We here aim at reviewing the current literature on the relationship between AR and conditions in upper airways frequently encountered in everyday clinical practice, and highlight the need for further studies exploring the role of allergic inflammation in the development of these diseases.

Up-Regulation of MUC5AC and MUC5B Mucin Genes in Nasopharyngeal Respiratory Mucosa and Selective Up-Regulation of MUC5B in Middle Ear in Pediatric Otitis Media with Effusion

OBJECTIVES

Mucins are the major component responsible for the gel-like properties of mucus secretion. Currently, little is known about the regulation of mucins in otitis media with effusion (OME). We investigated the expression of MUC5AC and MUC5B mucin gene messenger (m)RNAs in middle ear effusions as well as in tissue biopsies of the respiratory mucosa of the nasopharynx by means of reverse-transcription polymerase chain reaction (RT-PCR).

STUDY DESIGN

A prospective, controlled, clinical trial.

METHODS

The study group consisted of 25 children with a diagnosis of OME who were to undergo bilateral ventilation tube insertion with adenoidectomy. A sample of middle ear effusion (n = 50) as well as tissue biopsy from nasopharyngeal respiratory mucosa (n = 25) were obtained from each patient. For the nasopharyngeal mucosal biopsies, two control groups were made up from 30 children with healthy ears who underwent tonsillectomy +/- adenoidectomy operation; control A, 15 children with adenoid hypertrophy, and control B, 15 children with healthy nasopharynx. RNAs were extracted from effusion and tissue samples, and semiquantitative RT-PCR was performed for MUC5AC and MUC5B to investigate their expression.

RESULTS

In the middle ear effusions, MUC5B mRNA expression was detected in 48 (96%), whereas MUC5AC mRNA was detected in 8 (16%). On semiquantitative analysis, MUC5AC/glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and MUC5B/GAPDH mRNA ratios in the study group were significantly increased compared with those in both control groups (P < .05).

CONCLUSIONS

The results suggest that the middle ear has a unique mucin gene expression pattern when compared with that of the nasopharynx. Up-regulation of MUC5B in the ear may play an important role in the pathogenesis of middle ear effusions.

Eosinophil chemoattractants in the middle ear of patients with eosinophilic otitis media

BACKGROUND

Patients with intractable otitis media associated with bronchial asthma have an extensive accumulation of eosinophils in the effusion and mucosa of the middle ear; this condition is called eosinophilic otitis media (EOM). It remained to be determined how eosinophils accumulate in the middle ear.

OBJECTIVES

To clarify the pathogenesis of middle ear diseases, we measured the concentration of eosinophil chemoattractants in middle ear effusion (MEE), and carried out immunohistochemical studies of middle ear mucosa specimens to demonstrate the expression of eosinophil chemoattractants.

METHODS

Middle ear effusion samples were obtained from 15 EOM patients with bronchial asthma and from six controls for the measurement of eosinophil cationic protein (ECP), IL-5, eotaxin and regulated on activation, normal T expressed and secreted concentrations. Middle ear mucosa samples were also taken from 14 EOM patients and 16 controls for immunohistochemical study. In 10 EOM patients, the numbers of immunoreactive cells as well as apoptotic cells were determined before and after the topical application of triamcinolone acetonide into the middle ear.

RESULTS

In EOM, significantly higher ECP and IL-5 concentrations were detected in MEE than in serum, and ECP, IL-5 and eotaxin concentrations in MEE were higher in the EOM patients than in the controls. ECP concentration positively correlated with that of IL-5. Immunohistochemically, the numbers of cells positive for EG2 and ecalectin were significantly higher in the EOM patients than in the controls. After the topical application of triamcinolone acetonide, the numbers of infiltrating cells and immunoreactive cells distinctly decreased, whereas the number of apoptotic cells significantly increased.

CONCLUSION

In EOM, locally produced IL-5 may play a crucial role in the accumulation of eosinophils in the middle ear. Chemokines such as ecalectin and eotaxin are also produced in the middle ear, and help activate and enhance the survival of eosinophils to induce the intractable condition in the middle ear. The topical application of triamcinolone acetonide induces the apoptosis of not only eosinophils but also eosinophil chemoattractant-producing cells, thereby improving the middle ear condition.

Evidence of T-helper cell 2 cytokine regulation of chronic otitis media with effusion

Cytokine and cellular patterns of effusions may reflect stages of middle ear inflammation. The local interplay between IL-2 and -4 is likely to play a crucial role in the switching of inflammation in the chronic stage. The T-helper cell 2 (Th2) cytokines IL-4, -5 and -13 and the Th2/Th1 cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) regulate the cellular and molecular processes of chronic inflammation in the middle ear and therefore the chronic condition of otitis media with effusion (OME). Early identification of the cytokine and cellular patterns of effusions can be helpful in directing the clinical treatment of OME.We hypothesized that IL-2 and the group of Th2 cytokines regulate chronic inflammation in the middle ear and chronic OME. Effusions from children with persistent OME were analysed to determine the presence of cytokines (the Th1 cytokine IL-2, the Th2 cytokines IL-4, -5 and -13 and the Th1/Th2 cytokine GM-CSF), inflammatory cells (CD4+ T cells, eosinophils, macrophages and neutrophils) and mucin. Cytokines were evaluated by means of a quantitative "sandwich"-type ELISA, inflammatory cells by means of alkaline phosphatase-anti-alkaline phosphatase immunocytostaining and mucin by means of a modified periodic acid-Schiff method based on a slot-blot technique. The cytokine pattern in effusions varied from patient to patient. GM-CSF correlated positively and IL-4 inversely with IL-2 and the increased level of IL-4 may have had an inhibitory effect on IL-2. IL-5 and -13 correlated with IL-4. Inflammatory cells correlated with cytokines as follows: CD4+ T cells with IL-2 and -4; macrophages and neutrophils with GM-CSF; and eosinophils with IL-5. Some cytokine-cellular correlations in effusions were reflected at the clinical level. The mucin content of effusions correlated with the concentrations of IL-4 (>10 pg/ml) and -13, suggesting involvement of IL-4 and -13 in upregulation of the middle ear mucin metabolism.

The immunoregulatory and allergy-associated cytokines in the aetiology of the otitis media with effusion

Inflammation in the middle ear mucosa, which can be provoked by different primary factors such as bacterial and viral infection, local allergic reactions and reflux, is the crucial event in the pathogenesis of otitis media with effusion (OME). Unresolved acute inflammatory responses or defective immunoregulation of middle inflammation can promote chronic inflammatory processes and stimulate the chronic condition of OME. Cytokines are the central molecular regulators of middle ear inflammation and can switch the acute phase of inflammation in the chronic stage and induce molecular-pathological processes leading to the histopathological changes accompanying OME. In this review we present cytokines identified in otitis media, immunoregulatory [interleukin (IL)-2, IL-10, transforming growth factor-beta]) and allergy associated (IL-4, IL-5, granulocyte-macrophage colony-stimulating factor), as crucial molecular regulators, responsible for chronic inflammation in the middle ear and the chronic condition of OME.

The Etiology, Pathophysiology, and Management of Otitis Media with Effusion

Otitis media with effusion (OME) is a common and important condition that may result in developmental delay in children, and significant health care resources are devoted to its management. Newer techniques including polymerase chain reaction are implicating organisms not previously considered important in etiology. The role of gastroesophageal reflux as a cause of OME is likely to receive greater research attention. Regarding prevention, more is being learned about potentially modifiable risk factors such as environmental smoke, care outside the home, and breast feeding. Although immunization may to play a role in the future, existing evidence suggests that the general population of children should not be immunized in order to prevent OME. Several major studies have recently added to the understanding of epidemiology and management. Large trials in the United States, the Netherlands, and the UK suggest that OME is not an appropriate condition to include in a screening program. In addition, the advantages of early treatment with ventilation tubes over watchful waiting in terms of language development tend be modest and diminish by about 18 months. Treatment with hearing aids should be further evaluated. The search for effective medical management continues, and better ways are being identified of targeting interventions to those children with OME who are most likely to benefit.

Demonstration of RANTES and eosinophilic cataionic protein in otitis media with effusion with allergy

Regulated upon activation, normal T cell-expressed and -secreted (RANTES) is a chemokine which is an effective eosinophil and memory T cell chemoattractant and activator, and eosinophil is an important effector cell in allergic disease. It may contribute to the pathogenesis of otitis media with effusion (OME). Eosinophil cataionic protein (ECP), one of the major components of basic granules of eosinophils which is identified in middle ear effusion (MEE). We measured RANTES and ECP in MEEs of OME to determine whether RANTES is increased in the MEEs of OME with allergy. We also evaluated the correlation between RANTES and ECP to determine the role of RANTES as an eosinophil activator in the pathogenesis in OME with allergy. Both RANTES and ECP in MEE of OME with allergy were significantly higher than controls. There was a significant correlation between the contents of RANTES and ECP. Our results suggest the allergic role of chemokine in the pathogenesis of OME.

Relationships between atopy and bacterial infections

Atopy in its most common forms (asthma, allergic rhinitis, and atopic dermatitis) has a significant impact on society in terms of health care costs and quality of life. Aside from having significant morbidity from these diseases, patients with atopy have also been noted to have a high incidence of comorbidities, including bacterial infections such as otitis media and sinusitis. In this paper, current evidence is reviewed that supports the close associations among allergic rhinitis and the two commonly diagnosed bacterial diseases, otitis media and sinusitis.

IL-5 and eotaxin levels in middle ear effusion and blood from asthmatics with otitis media with effusion

OBJECTIVE

The purpose of this study was to evaluate eosinophil infiltration as well as IL-5 and eotaxin levels in middle ear effusion (MEE) and blood from otitis media with effusion (OME) patients with asthma and to compare the findings with those from OME patients without asthma (control group).

MATERIAL AND METHODS

Levels of IL-5 and eotaxin in MEE and blood were measured by means of enzyme-linked immunosorbent assay.

RESULTS

5 levels in MEE were significantly higher than those in blood in both groups of patients and in OME patients with asthma than in the control group. In addition, in OME patients with asthma, there was a significant correlation between the percentage of eosinophils and IL-5 levels in MEE. Eotaxin levels in blood were significantly higher than those in MEE in both groups of patients and in OME patients with asthma than in the control group. In addition, in OME patients with asthma, the percentage of eosinophils and eotaxin levels in blood tended to correlate, but did not reach statistical significance.

CONCLUSION

These data suggest that, in OME patients with asthma, eosinophilia in MEE depends more on IL-5 than on eotaxin, and that eotaxin may play an important role in the mobilization of eosinophils from the bone marrow into the blood.

Characterization of cytokines present in pediatric otitis media with effusion: comparison of allergy positive and negative

To investigate the possible relationship between allergy and otitis media with effusion (OME), we investigated the cytokine level in the middle ear effusion (MEE)s of children with persistent OME. Interleukin (IL)-2, IL-4, IL-6 and tumor necrosis factor (TNF)-alpha in the MEEs were measured by devised sensitive sandwich enzyme-linked immunosorbent assay (ELISA) and compared allergy positive group with allergy negative group. The mean levels of IL-4, IL-6 and TNF-alpha in MEE were significantly higher in allergy positive group than allergy negative group (P<0.05). Elevation of Th-2-driven cytokines (IL-4, IL-6) and TNF-alpha in MEEs may be a contributing factor in the persistence of OME with allergy.

T(H)2 cytokine expression in atopic children with otitis media with effusion

BACKGROUND

Otitis media with effusion (OME) is more common in atopic children. Few studies have looked for the presence of inflammatory mediators in the middle-ear effusions of this population.

OBJECTIVE

We hypothesize that atopic children with OME have a different inflammatory cell and cytokine profile than nonatopic patients with the disease.

METHODS

Twenty-six patients with OME undergoing myringotomy and ventilation tube placement were recruited at the McGill University Hospital Center. The atopic status was determined for each patient by using standard skin testing. By means of immunocytochemistry, fluid specimens were assessed for T lymphocytes (CD3), eosinophils (major basic protein), neutrophils (elastase), mast cells (tryptase), and basophils (BB1). By using in situ hybridization, the expression of IL-4, IL-5, and IFN-gamma was assessed.

RESULTS

There is a higher percentage of eosinophils and T lymphocytes in atopic patients with OME (n = 8) compared with that seen in nonatopic patients (n = 18, P <.01). There is a higher percentage of neutrophils in nonatopic patients with OME compared with that seen in atopic patients (P <.01). In examining cytokine profiles, there is a higher percentage of cells expressing IL-4 and IL-5 in atopic patients with OME compared with that seen in nonatopic patients (P <.01).

CONCLUSION

The predominance of eosinophils, T lymphocytes, and T(H)2 mediators in the middle-ear effusions of atopic children provides evidence that allergy might play a role in the pathogenesis of OME.

The link between allergic rhinitis and otitis media

Past studies implicated allergy in the pathogenesis of otitis media. However, definitive proof of the assertion is lacking. Epidemiologic studies, including one recently published by Rylander and Megevand, consistently identify allergy as a risk factor for otitis media. Also, higher than expected frequencies of allergy are reported for patients with otitis media, but it is unclear if this is an epiphenomenon associated with referral bias. This possibility is exemplified by the results of two reviewed papers where Velepic and colleagues reported a 25% prevalence of allergy in otitis media patients while Alles and colleagues reported a prevalence of 89%. Other studies documented biochemical components of allergic inflammation in the effusions recovered from children with otitis media, and Hurst and colleagues published a recent paper continuing on that theme. However, it is not known if a local allergic reaction is required for the production of these components and if they are produced exclusive of other inflammatory products. Three published studies explored mechanisms by which allergy could cause otitis media. Tikkanen and colleagues reexamined at age 10 a group of 56 subjects with previously diagnosed milk allergy and showed that despite decreased reactivity to milk protein a high prevalence of otitis media was retained. This suggests that it is the allergic condition, not the specific allergy to milk that increases otitis media risk. Downs and colleagues exposed the middle ears of rats to histamine and provoked changes in the pressure regulating and clearance functions of the Eustachian tube. Those changes could prolong an otitis media episode, but middle ear histamine is not limited to the allergic condition. Gentile and colleagues challenged the nose of allergic and nonallergic subjects with histamine followed by interleukin-6 or placebo and measured nasal, pulmonary, Eustachian tube and middle ear functions. Interleukin-6 did not change the Eustachian tube or middle ear functions but did cause increased secretions in allergic patients.