title: Effects of low humidity on the rat middle ear.
abstract: Secretory otitis media is common in the winter, and the possible risk factors are numerous. This study examines the effect of low humidity on the middle ear using a Sprague-Dawley rat model: 23 test rats housed for 5 days in a low-humidity environment (10% to 12% relative humidity) and 23 control rats housed at 50% to 55% relative humidity. Microscopic ear examinations were graded for otitis media with effusion (OME) before testing and on test days 3 and 5. The mucosa of the middle ears and eustachian tubes was examined histopathologically. Significantly more effusions were observed in the low-humidity group on test days 3 (P = .003) and 5 (P = .01), but no intergroup histopathologic differences were noted. We conclude that a low-humidity environment contributed to the development of OME in the test animals, and that low-humidity warrants further investigation as a contributing factor in childhood middle ear disease.
authors.affiliation: Department of Otolaryngology, Wake Forest University Medical Center, Winston-Salem, NC.
authors.forename: H M
authors.initials: HM
authors.lastname: Lovejoy
authors.forename: W F
authors.initials: WF
authors.lastname: McGuirt
authors.forename: P H
authors.initials: PH
authors.lastname: Ayres
authors.forename: A W
authors.initials: AW
authors.lastname: Hayes
authors.forename: C R
authors.initials: CR
authors.lastname: Coggins
authors.forename: J
authors.initials: J
authors.lastname: Sagartz
mesh_terms: D000818:Animals; D004432:Ear, Middle / Q000033:anatomy & histology / Q000502:physiology*; D004848:Epithelium / Q000473:pathology; D005064:Eustachian Tube / Q000473:pathology; D005122:Exudates and Transudates; D006813:Humidity; D006940:Hyperemia / Q000473:pathology; D008297:Male; D008307:Malleus / Q000473:pathology; D009092:Mucous Membrane / Q000473:pathology; D010034:Otitis Media with Effusion / Q000209:etiology* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014432:Tympanic Membrane / Q000098:blood supply / Q000473:pathology