Otitis media is an inflammation that occurs in the middle ear. Middle ear space contains fluid that could be easily infected and the infected middle ear is called otitis media with effusion. The cause of the chronic OME (otitis media with effusion) for most of the allergic rhinitis patients is mainly due to the IgE-mediated allergies. IgE-mediated allergy is the allergy that happens when IgE antibody (one type of the white blood cell) binds with the mast cell. IgE antibody is being produced by the plasma cell when foreign particular from outside of the body entering into the blood through nasal mucosal surface. Once the IgE antibody binds with the mast cell around the nose, histamine is secreted from this cell and it is the main chemical that causes itching and hypersensitive of the nose. According to the publication by a group of scentists, 50% of the children who had chronic OME also had nasal allergy [Acta Otolaryngol (Stockh) 1988;458(suppl):41-7]. Effects of the seasonal allergic rhinitis to the Eustachian tube function and middle ear pressure had been studied by a few groups of medical scientists. According to one of the studies, Eustachian tube of the pollen allergic patients become obstructed increases from 15% to 60% from the starting to the maximum of the pollen exposure. [Ann Allergy 1990;65:206-10]. In one of the studies, ragweed pollen , which is a seasonal pollen, was let it exposed to a group of people. What had been discovered is that it will cause immune reactions in the Eustachian tube and nose [Am J Rhinol 1988;2:155-61.].Apart from this study, the other study reported that house-dust mite, which was a perennial allergen, also caused Eustachian tube obstruction [ ArchOtolaryngol Head Neck Surg 1986;112:840-]. In the same study, they found out that 55% of the adults, who had nasal allergy, experienced the development of the Eustachian tube dysfunction when this group of adult was exposed to house-dust mite. In the following study, new thing that had been found out was Eustachian tube obstruction happened more frequently for the patients who had allergic rhinitis. [J. Allergy Clin Immunol 1987;79:27-31]. In allergen provocation studies, scientist found out that nasal obstruction usually occurred before the development of the Eustachian tube obstruction. In allergen provocation study, individuals who took part in this study were exposed to allergen to provoke their nasal allergy symptom. In this study, researchers also discovered that various of inflammatory mediators such as histamine have been detected in middle ear effusions of the children who had OME [Arch Otolaryngol Head Neck Surg 1988;114:1131-3]. If Eustachian tube obstruction that was caused by perennial exposure to allergen such as house-dust mite was left it untreated for quite a sometime, it could form middle ear disease, especially, when priming phenomenon occurs in the Eustachian tube. Priming phenomenon happens when mucosa in the organ responds to lower doses of allergen with repeated exposure. Allergic rhinitis could have priming phenomenon too when the mucosa in the nasal passage responds to low amount of allergen that has been inhaled through the nostril. For the Eustachian tube obstruction that was caused by seasonal exposure to allergen such as ragweed pollen, its physiologic hyperresponsiveness could extend beyond the ragweed season.
