Effects of Ototopical Antihistamine on Otitis Media in an Allergic Rat

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.

Role of Allergy in Eustachian Tube Dysfunction

PURPOSE OF REVIEW

Eustachian tube dysfunction (ETD) presents with symptoms of aural fullness and pressure, muffled hearing, tinnitus, and otalgia. When severe, it can lead to many common ear disorders such as otitis media with effusion, tympanic membrane retraction/perforation, and cholesteatoma. These diseases are prevalent in both the pediatric and adult population and significantly impact quality of life. The pathophysiology of ETD in the absence of an obstructive lesion has long been debated but is thought to be related to functional obstruction (i.e., inefficient tensor veli palatini muscle) and/or nasal cavity and nasopharyngeal inflammation. In the acute setting, the most common cause of nasal inflammation is an upper respiratory infection. When symptoms become chronic, however, the inflammation is thought to be associated with nasal irritants such as nasal allergens, i.e., allergic rhinitis (AR). The purpose of this review is to summarize our current understanding of the relationship between allergy and ETD.

RECENT FINDINGS

Past studies are either lacking or have reported equivocal findings regarding the relationship between allergy and ETD, and the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis has deemed the current level of evidence linking AR and ETD as low quality. A more recent study using a large adult population dataset did support an association between AR and ETD, but did not find that all cases of ETD are related to allergies. Furthermore, current evidence suggests that the use of medications that can decrease intranasal inflammation, such as intranasal corticosteroids or oral antihistamines, does not result in significant symptomatic improvement in patients with ETD. However, these studies included all patients with ETD, and evidence is lacking regarding the treatment effect of these medications on the subset of patients with concurrent AR and ETD. Current best evidence does support an association between AR and ETD; however, not all patients with ETD suffer from AR, and vice versa. Further research is necessary to understand the mechanism behind this positive association and to elucidate the cause of chronic ETD in patients without associated allergies.

The Proposed Usage of Intranasal Steroids and Antihistamines for Otitis Media with Effusion

PURPOSE OF REVIEW

To examine the role of allergy medications in the treatment of otitis media with effusion (OME), focusing on use of intranasal steroids and antihistamines.

RECENT FINDINGS

There has been ongoing controversy regarding the role of allergy in the development of OME. Treatment of OME with medications commonly used for allergic symptomatology has been studied. Proposed treatment options include decongestants, mucolytics, oral steroids, topical steroids, antihistamines, and antibiotics. We begin by evaluating the proposed association between allergy and OME, and then evaluate intranasal steroids and oral antihistamine therapy in the treatment of OME. The role of the adenoid and concurrent nasal symptomatology is also addressed. The preponderance of data suggests that neither intranasal steroids nor antihistamines improve the long-term clearance of isolated OME and are therefore not recommended. However, data are notably limited with regard to improvement rates in OME in patients specifically with concurrent allergy and/or adenoid hypertrophy. Future studies of medications for OME would ideally incorporate study designs controlling for both allergic rhinitis and adenoid hypertrophy, to better understand the impact of these medications on OME in these subgroups of patients.

The role of food allergy in otolaryngology disorders

PURPOSE OF REVIEW

Food allergy is often an unrecognized clinical entity that has been implicated as a cause in many types of chronic inflammatory conditions. This review serves to provide an update on how food allergy plays a role in otolaryngology disorders.

RECENT FINDINGS

The incidence of food allergy has been on the rise over the last decade. Currently, about 6% of children and 3-4% of adults are thought to be affected by food allergy. The middle and inner ear are immunologically responsive and this includes responsiveness to food hypersenstivities. Both chronic otitis media with effusion and Meniere's disease can improve with treatment of food allergies. Some evidence supports a link between rhinitis and nasal polyps and food allergies. Finally, there is increasing literature about eosinophilic esophagitis, which is a relatively newly recognized disease with many otolaryngologic associations. Many of these patients may have food allergy, and treatment of their food allergy may be effective in treating the disease.

SUMMARY

In chronic inflammatory disorders of the head and neck, especially those involving the upper aerodigestive tract, food allergy must be considered in the differential. Patients with food allergy often do not respond to conventional treatments, and it can often be a challenge to arrive at the proper diagnosis. Further research is warranted to improve our understanding of the role of food allergy in otolaryngology disorders, as well as our diagnostic and treatment methods.

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.