Early fever protects against allergies,
from the Journal of Allergy and Clinical Immunology

(MILWAUKEE) - Children who have a fever before age one are less likely to develop allergies at age 6-7 years, according to a study featured in the February 2004 Journal of Allergy and Clinical Immunology (JACI). The JACI is the peer-reviewed journal of the American Academy of Allergy, Asthma and Immunology (AAAAI).

L. Keiko Williams, MD, MPH, Henry Ford Hospital, Detroit, and colleagues, enrolled 835 children at birth to determine if fever before age 1 was associated with allergic sensitization later in life. Of the 835 children, 441 underwent clinical evaluation at age 6 to 7 years.

The study noted that fever was common in the first year of life, affecting 207 (46.9%) of the 441 children. By age one, there were 321 episodes of fever among these 441 children, most commonly associated with infection of the ears, upper respiratory tract and lower respiratory tract.

When evaluated at age 6 to 7 years of age, 31.5% of the children had atopy (positive skin prick test), 39.2% had seroatopy (positive allergen-specific IgE test), and 45.8% had allergic sensitization (either atopy or seroatopy). Researchers discovered that allergic sensitization and atopic asthma were significantly less common among children who had fevers in their first year. They also found that each time a child had a fever; the odds of them developing allergies later in life were reduced.

These findings provide direct support for the hygiene hypothesis, which suggests that exposure to infections early in life decreases the risk of developing allergies. More information is needed about the types of infections that protect against allergies and the pathways by which they mediate their effect.

The AAAAI represents allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic disease. Established in 1943, the AAAAI has more than 6,500 members in the United States, Canada and 60 other countries. The AAAAI serves as an advocate to the public by providing educational information and a physician referral directory through its Web site at www.aaaai.org.

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