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Relationship Between Exhaled Breath Temperature and Ear Temperature in Otherwise Healthy Persons during Febrile Infectious Illness
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Todor A. Popov, MD, PhD, Tanya Kralimarkova, Lawrence M. DuBuske, MD, FAAAAI
Rationale: Exhaled breath temperature (EBT) is proposed as a non-invasive marker of inflammation in obstructive airway diseases. EBT and core body temperature (CBT) are not identical in normal persons. This study assesses associations between EBT and CBT during febrile illnesses.

Methods: Six generally healthy subjects, including 5 men, aged 42–64 years, had daily EBT assessed for 5 months and 2 years. All used hand-held devices specifically engineered for personal use, the X-halo®, DMI Singapore. They measured ear temperature (ET) to assess CBT. The EBT devices had data uploaded automatically on an Internet site. The subjects were instructed to record ET at 8-hour intervals if the measurement exceeded 37ºC. Frequency of  EBT measurements were increased during febrile illnesses.

Results: Six episodes of fever were documented during the study: 2 cases of rhinovirus infections in which EBT rose by 1.2-1.9ºC above baseline, preceding by 24-72 hours a moderate increase of ET (up to 38ºC); 2 cases of influenza in which EBT rose by >2.0ºC about 6 hours before ET (up to 40ºC); and 2 cases of bacterial infections, urinary and GI, in which EBT rose by ≈1.0ºC simultaneously with ET (up to 39ºC).

Conclusions: EBT rises during incipient viral infections earlier than CBT as seen by ET, providing a window of opportunity for early treatment. EBT assessment allows early detection of illness in patients at risk of exacerbation of underlying obstructive airway diseases.