Recent studies have suggested that the middle ear is a target organ of allergy. Regardless of whether the relationship between allergy and OME is direct or indirect, the otitis prone child is predominately (80-90%) an allergic child whose prime eosinophils, mast cells and neutrophils for as yet as undetermined reasons respond in a manner unique from nonallergics.
Otitis media with effusion is the major form of chronic relapsing inflammatory disease of the middle ear, constitutes the most common diagnosis for children under 15 years old and is the major cause of auditory dysfunction in pre-school children. It accounts for more than 28 million visits to a physician by children, the greatest number of surgical procedures involving children, and accounts for an expenditure on health care exceeding $5 billion in the USA alone.
The theory that allergy is an important factor in the development and maintenance of OME is elegant in its simplicity. It is a theory which seems to tie in the various, seemingly unrelated, risk factors known to be associated with this disease, namely: family history of otitis, a history of rhinitis or asthma, family smoking, sudden increase in developed countries, family history of atopy, and associated viral infection. Stenström showed OME to be 4 times more likely in allergic children, and that “otitis prone” children were 2.5 times more likely to have asthma or rhinitis than controls.[Stenström, 1994] Kraemer found the risk of OME to increase 2.8 to 4.2 times if parents smoked 2 or 3 packs of cigarettes. Similar risk of rhinitis or asthma symptoms occurring in children in the same smokers’ family was increased 1.4 to 3.7 times.[Kraemer, 1983] Kulig[Kulig, 1999] found smoking to have an adjuvant effect on allergic sensitization of infants. Children were 2.2 times more likely to be allergic to foods if exposed to parental smoke, and 1.8 to 2.2 times more allergic than controls if exposed to cats or dust mites.
The American Academy of Allergy and Immunology has officially recognized that inflammation in the middle ear is simply an extension of chronic mucosal disease of the nasal and upper airway passages. Furthermore, it has been demonstrated that the mucosa of the middle ear is capable of mounting an allergic immunologic response similar to that seen in the rest of the upper respiratory system mucosa when confronted by an antigen challenge.
Research into the etiology of chronic OME has provided evidence which debunks several commons myths. We know that “eustachian tube dysfunction does not adequately explain the pathology of otitis media with effusion nor can adenoids acting as direct obstruction,” that “chronic inflammation in the middle ear is a direct continuation of the acute episode in only half of the cases and is not the result of inadequate therapy,” that there is no organic obstruction or stenosis of the eustachian tube in OME patients, that only 11% of active OME patients have abnormally high opening pressures, that the eustachian tube of OME patients does not have an “immature morphology,” that there are several double blind placebo controlled studies which show internasal pollen challenge to produce eustachian tube obstruction in allergic patients, and that review of the literature finds over a dozen studies which identify that OME patients are indeed allergic between 74 and 100% of the time. Seven of these studies found that allergy management was successful in relieving the disease in 75-90% of patients. Rather, it is the host’s immunologic response which appears to account for the differences in prognosis.
Having evidence that otitis media with effusion is a sign of allergy and having evidence that the middle ear mucosa, like a “5th sinus,” appears to be capable of responding in a manner similar to the rest of the respiratory tract and participate in an allergic response, the standard evaluation for a patient demonstrating persistent effusion with or without purulence warrants a full evaluation for foods and inhalant allergies. To be efficacious, antibiotics should be used for infection; antihistamines, steroids, and immunotherapy should be reserved for allergy.