Effect of the status after ear surgery and ear pathology on the results of infrared tympanic thermometry.

Most publications that deal with infrared tympanic thermometry (ITT) have performed a comparison between the established temperature measurements and ITT. However, to date an understanding of the influence of pathological ear findings on ITT test results is incomplete. Therefore, in the present study ITT was performed in healthy adults (n =21), adult patients with monaural central perforation (n =31) or strong scar formations (n =24) of the tympanic membrane and 18 adult patients after monaural canal wall down surgery. Right and left ear and oral temperature were measured three times by one investigator in a room with a constant temperature of 20-22 degrees C. Between every measurement there was a free time interval of 2 min. In healthy adults (36.50 degrees C vs. 36.51 degrees C) patients with monaural central perforation of the tympanic membrane (36.41 degrees C vs. 36.34 degrees C) and with monaural strong scar formations in the tympanic membrane (36.39 degrees C vs. 36.45 degrees C), no significant difference between the right and left ear could be proved. In contrast to this, a significantly higher temperature in the surgically treated ear compared to the healthy side (36.97 degrees C vs. 36.31 degrees C; P <0.001) occurred in patients with a status of after monaural canal wall down surgery. In summary, it could be demonstrated that, in contrast to minor ear surgery, major ear surgery such as canal wall down has a significant influence on the results of ITT. If a patient's history gives reference to previous ear surgery, an otoscopic examination is necessary in order to exclude the presence of an after-canal-wall-down surgery status and thus to avoid false ITT test results.