Middle Ear Effusion Induced by a Stream of Air in the External Auditory Canal A Temperature-related Phenomenon

Abstract

The blowing of chilled (14°C) air into the external auditory canal (EAC) resulted in a profuse middle ear fluid production. The stimulation caused marked changes in the pars flaccida of the tympanic membrane. A slight vasodilatation was noted in the oedematous loose connective tissue layer of the pars flaccida. The abundant mast cells showed no signs of degranula-tion. When stimulating animals with air at 22°C, only minimal effusion production and tympanic membrane changes could be induced. At 34°C, no changes ocurred at all. Thus it was shown that temperature is an important factor when provoking middle ear effusion by stimulating the EAC. As fluid production is one of the major signs in OME, one may speculate whether temperature may be an overlooked etiologic agent in this disease.

Key Words:

• external auditory canal
• tympanic membrane
• pars flaccida
• mast cells
• middle ear effusion
• temperaturedependency