Huang SY, Greenes DS. Effect of recent antipyretic use on measured fever in the pediatric emergency department. Arch Pediatr Adolesc Med. 2004;158:972-976.

Many infants are brought to the emergency department (ED) with fever. However, there are no data on whether the prior use of antipyretics by parents in the home has an influence on the extent of fever measured in the ED.

This prospective study gathered information on 474 infants younger than 1 year who were seen in the ED for temperature greater than 38[degrees]C. Data were also gathered on the frequency, type, and dose of an antipyretic given by the parents before coming to the ED.

The findings showed that 71% of the infants still had a temperature of 38[degrees]C or higher in the ED and that 31% had temperature higher than 39[degrees]C. A majority of the infants (57%) were suffering from fever due to a virus or other febrile illness. Other causes were otitis media, upper respiratory infections, and gastroenteritis.

When parents were asked whether they had given acetaminophen or ibuprofen to their infants in the 6 hours prior to coming to the ED, 41% said "yes." However, of those parents who remembered the dose given to the infants, it was found that about 75% had given doses too low or too long ago to be helpful in reducing the fever.

Of most interest was the finding that infants whose parents reported fever and who had also been given an antipyretic had higher fever when seen in the ED than infants who had not received acetaminophen or ibuprofen. The researchers hypothesized that fever was more likely to be treated by parents before coming to the ED. More research is needed to investigate whether parents are fully informed about how to treat infants with fever, including the proper doses and frequencies to give antipyretics to infants. Emergency department personnel also need to be aware that infants with fever might, in reality, have higher temperature than measured because of the possibility that the antipyretics given by parents may have reduced the temperature.