Increase in allergic sensitization in schoolchildren : two cohorts compared 10 years apart

• BACKGROUND: Time trends of incidence of allergic sensitization are unknown and recent trends of prevalence and risk factors are lacking.OBJECTIVE: To estimate the incidence, prevalence, remission, risk factors, and time trends for allergic sensitization among schoolchildren followed from age 7 to 8 years to age 11 to 12 years.METHODS: In 2006, all children in grades 1 and 2 aged 7 to 8 years in 2 municipalities in northern Sweden were invited to a questionnaire survey and to skin prick testing to 10 common airborne allergens. The cohort was reexamined in 2010, with additional blood sampling for specific IgE. Participation rates were 90% (n = 1700) at age 7 to 8 years and 85% (n = 1657) at age 11 to 12 years. The results were compared with a cohort examined by identical methods 10 years earlier.RESULTS: The prevalence of positive skin prick test result to any allergen increased from 30% at age 7 to 8 years to 41% at age 11 to 12 years (P < .001). The cumulative 4-year incidence was 18%, while remission was low. Sensitization to pollen and furred animals was most common. A family history of allergy was significantly associated with incident sensitization, whereas the presence of furred animals at home was negatively associated. The prevalence at age 7 to 8 years and at age 11 to 12 years and the 4-year incidence were all significantly higher compared with the cohort examined 10 years earlier.CONCLUSIONS: The prevalence of allergic sensitization increased by age as a consequence of a high incidence and a low remission. The trends of increasing incidence and prevalence among schoolchildren imply future increases in the prevalence of allergic diseases.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Arbetsmedicin och miljömedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Occupational Health and Environmental Health (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Omvårdnad (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Nursing (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Lungmedicin och allergi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Respiratory Medicine and Allergy (hsv//eng)

Keyword

Allergic sensitization

Prevalence

Incidence

Risk factors

Longitudinal study

Schoolchildren

Nursing

Allergic sensitization; Incidence; Longitudinal study; Prevalence; Risk factors; Schoolchildren

Publication and Content Type

ref (subject category)

art (subject category)