CERUMEN OCCLUSION LOWERS INFRARED TYMPANIC MEMBRANE TEMPERATURE-MEASUREMENT

Objective: To examine the effect that cerumen occlusion of the ear can al has on infrared tympanic membrane temperature measurement. Methods: A prospective, randomized, single-blind human study was carried out i n a university hospital observation unit. The subjects were a convenie nce sample of human volunteers aged 18 years or older who did not have cerumen occlusion or scarred tympanic membranes. A paraffin-coated hu man cerumen plug was placed in one randomly chosen ear, and after 20 m inutes of equilibration the temperature in each ear was measured with an infrared thermometer. Analysis of the difference in mean temperatur e between the occluded and nonoccluded ears was by Student's paired t- test. Results: Infrared tympanic membrane temperatures were measured i n 43 subjects aged 21 to 58 years. The mean temperature of the occlude d ear canal was 0.3 degrees C lower than that of the opposite ear cana l (p = 0.0001, 95% CI 0.16-0.45 degrees C). Conclusion: Cerumen occlus ion of the ear canal causes underestimation of body temperature measur ed by infrared tympanic membrane thermometry.