Does nasal allergy contribute to secretory otitis media in adults?

This study from the Netherlands lends support to the hypothesis that nasal allergy plays a role in chronic secretory otitis media in adults. Nasal allergen challenge combined with tympanometry appears to be a valuable diagnostic tool in this setting.

Pelikan studied 69 patients, 16 to 26 years of age, who had a history of bilateral chronic secretory otitis media and had recurrent symptoms of rhinitis, particularly nasal obstruction. A control group consisted of 42 patients with allergic rhinitis and no history of middle ear disease. The study participants underwent nasal allergen challenge, performed by anterior rhinomanometry, and tympanometry.

The patients with secretory otitis media underwent 173 nasal challenges. There were 129 positive nasal responses in 54 of the 69 patients; 117 of these responses were accompanied by significant changes in middle ear pressure. In the control group, there were no significant tympanometric changes associated with 42 positive nasal responses.

Pelikan notes that there are several possible mechanisms underlying the role of allergy in secretory otitis media. For example:
• The allergic reaction may occur primarily in the eustachian tube or the middle ear cavity.
• The allergic reaction may occur in the mucosal membrane of the nasopharynx or its related structures. The release of mediators may have a secondary effect on the mucosa of the eustachian tube, with progression into the middle ear  cavity.
• The allergic reaction may occur primarily in the nasal mucosa. This may trigger mediator release, resulting in nasal obstruction.

Are thunderstorms an important asthma trigger?

Pulimood TB, Corden JM, Bryden C, et al, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, and other centers. Epidemic asthma and the role of the fungal mold Alternaria alternata. J Allergy Clin Immunol. Sept 2007;120:610-617.

In July 2002, a thunderstorm in eastern England was accompanied by a sudden increase in asthmarelated admissions at several hospitals. The results of a subsequent case-control study by Pulimood and associates suggest that sensitivity to Alternaria species played a major role in these asthma exacerbations.

The study included 26 patients who presented to the hospital with asthma after a thunderstorm and a control group of 31 patients with seasonal (summer) asthma. The participants underwent skin testing and specific IgE serological testing to inhaled aeroallergens.

The investigators found that 23 of 26 patients had IgE sensitization to Alternaria species. Eleven of 31 patients in the control group reported having asthma exacerbations during thunderstorms. Skin test sensitivity to Alternaria species was identified in 10 of the 11, compared with only 4 of the 20 patients who did not report thunderstorm-related asthma exacerbations.

The odds ratio for epidemic thunderstorm-related asthma was 9.31 in the presence of sensitivity to Alternaria species and 63.96 in the presence of sensitivity to Alternaria species and/or Cladosporium species. Analysis of meteorological and aerobiological data revealed that the thunderstorm was associated with elevated levels of Alternaria, Cladosporium, and Didymella species.

The investigators note that environmental levels of the fungal spores of Alternaria and Cladosporium species increase rapidly at the end of the grass pollen season. This can trigger asthma, followed by increased bronchial hyperreactivity, in sensitive persons. A thunderstorm occurring at the time of harvesting, with high fungal spore counts and fragmented Alternaria species, can be an especially potent asthma trigger.