Timing and intensity of early fevers and the development of allergies and asthma.
BACKGROUND
Early childhood fevers appear to protect against later allergies and asthma. What is not known is the time in which fevers exert this effect and whether the degree of temperature increase is important.


OBJECTIVE
We sought to examine the relationship between the time and degree of early fevers and later allergies and asthma.


METHODS
Eight hundred thirty-five children from southeast Michigan were enrolled at birth. Clinic records from their first 2 years were abstracted for episodes of fever. At age 6 to 7 years, children underwent allergy testing. We examined fevers occurring within 6-month intervals in the first 2 years of life and outcomes at age 6 to 7 years. The primary outcome measures were allergic sensitization, asthma, asthma with allergic sensitization, and asthma without allergic sensitization.


RESULTS
In the unadjusted analysis each episode of fever between 7 and 12 months of age was associated with a lower odds of allergic sensitization (odds ratio [OR], 0.71; 95% CI, 0.54-0.93) and asthma with allergic sensitization (OR, 0.43; 95% CI, 0.21-0.90) at age 6 to 7 years. Likewise, every 1 degrees C increase in the maximum temperature between 7 and 12 months was associated with a lower odds of allergic sensitization (OR, 0.77; 95% CI, 0.61-0.96) and asthma with allergic sensitization (OR, 0.62; 95% CI, 0.40-0.94). After adjusting for potential confounders, each episode of fever between 7 and 12 months was associated with a lower likelihood of asthma with allergic sensitization (adjusted OR, 0.33; 95% CI, 0.11-0.94) at age 6 to 7 years.


CONCLUSIONS
Both the timing and intensity of childhood fevers appear to be important factors in the development of allergies and asthma.
Williams
L Keoki
LK
Department of Internal Medicine,Center for Health Services Research, Henry Ford Health System, Detroit, MI 48202, USA. kwillia5@hfhs.org
Peterson
Edward L
EL
Pladevall
Manel
M
Tunceli
Kaan
K
Ownby
Dennis R
DR
Johnson
Christine C
CC
D001249:Asthma / Q000453:epidemiology* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005334:Fever / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013997:Time Factors