Taking the temperature of infants and young children with ear thermometers may be unreliable and lead doctors and parents to miss signs of fever, researchers say today.
The inconsistency of readings obtained from the increasingly popular devices in which the tips are gently inserted into patients' ears could lead to doctors making mistaken judgments on whether their patients need further investigations, antibiotics or even admission to hospital, according to a team from Liverpool University.
The accurate measurement of temperature is vital in new-born babies and children with weak immune systems but uncooperative or restless infants can make this process extremely difficult. Infrared aural thermometers have therefore seemed a boon, even if they are known to provide slightly different results than the more tried and trusted clinical method of inserting a thermometer into the rectum.
Aural thermometers are also used by parents on their own children since it is tricky to measure temperatures of chil dren under five with traditional "under the tongue" thermometers.
Temperatures above 37C (98.6 F) are often a sign of infection and though the Liverpool review of data involving the temperatures of 4,441 children suggested that on average the ear temperature was 0.29C lower than the rectal temperature, variations could be extremely wide. For instance, if the temperature measured at the rectum was 38C, the temperature at the ear could range from 37.04C to 39.2C .
Rosalind Smyth, who led the research reported in the Lancet medical journal, said she was not advocating "people should now just stop using them", because many doctors or parents could measure trends in temperature readings, rather than depend on one reading. "However, in situations where temperature needs to be measured accurately and management [of patients] would be changed by the results of a single reading, one needs to be cautious."
The finding "means that the presence of fever might not be detected, and accurate temperature might not be obtained in situations in which body temperature needs to be measured precisely."
Further research was needed.
