Quantitative definition of fever needs a change

BackgroundThe age-old definition of fever was derived using cross-sectional population surveying utilizing old techniques without considering symptomatology. However, the diagnosis of fever must be made only in the presence of associated symptoms that can distinguish it from the mere asymptomatic physiologic rise of temperature. Association of the temperature values with the symptoms to define the cut-off for fever is need of the hour. MethodsA longitudinal study on the healthy population of Northen-India were followed-up over 1-year. Participants were advised for self-monitoring of oral temperature with a standard digital thermometer in either left or right sublingual pocket and record it in the thermometry diary. The study was considered complete if the participant had all the three phases of the study (i.e. non-febrile, febrile, and post-febrile phases) or completed the duration of the study. ResultsPer protocol analysis done for febrile participants (n=144, temperature recordings= 23851). The mean febrile phase temperature was 100.25 {+/-} 1.440F. A temperature of 99.10F had maximum diagnostic accuracy for feeling feverish (98.2%), along with one (98.3%) or two (99%) associated symptoms. Summer and spring months showed higher temperatures (100.38 {+/-} 1.44 v/s 99.80 {+/-} 1.49, P<0.001), whereas no significant temperature difference could be noted amongst the gender. ConclusionsA revised cut-off for the temperature to decide fever is hereby proposed: 99.10F along with one or two associated symptoms. This is going to redefine fever in the modern era completely.