Natural history of hay fever and pollen sensitization, and doctors' diagnosis of hay fever and pollen asthma in German schoolchildren.
BACKGROUND
In order to prevent pollen asthma by immunotherapy it is mandatory to know the best time to initiate it. Children with hay fever complaints are at considerable risk of developing pollen asthma. Population-based data on their natural history is urgently needed.


METHODS
A longitudinal cohort study was conducted over four years in six rural towns in Baden-Württemberg, Germany. A questionnaire with questions taken from the International Study of Asthma and Allergies in childhood (ISAAC) was filled in every spring and autumn. Hay fever complaints, asthma defining symptoms and new doctors' diagnosis of hay fever and asthma were recorded. Additionally a skin prick test with pollen allergens was performed every autumn.


RESULTS
In 1996, 19.7% of 1101 elementary school children (age: 8.1-9.9 years (5-95%)) were found to be sensitized to pollen and 8.7% had already been diagnosed as having hay fever. In a pooled analysis of 2478 children-summers, children with positive pollen sensitization had a significantly higher risk of developing hay fever symptoms (2.63; 2.17-3.10 odds ratio (OR); 95% confidence interval (CI)) and of being diagnosed as suffering from hay fever (7.88; 4.70-13.20). Furthermore, although their OR for the development of asthma symptoms during the pollen season was 3.88 (2.48-6.07 CI), it was only 0.69 (0.24-2.01 CI) for doctors' diagnosis of pollen asthma.


CONCLUSIONS
Children of elementary school age with pollen sensitization and a history of hay fever are at considerable risk of getting pollen asthma, but they are not quickly diagnosed as such. Specific immunotherapy might be a means of preventing asthma completely in such a situation. Our data helps to estimate the sample size for intervention studies of this kind.
Riedinger
F
F
University Children's Hospital Freiburg, Germany.
Kuehr
J
J
Strauch
E
E
Schulz
H
H
Ihorst
G
G
Forster
J
J
D000393:Air Pollutants / Q000009:adverse effects / Q000276:immunology; D000485:Allergens / Q000009:adverse effects* / Q000276:immunology*; D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D002648:Child; D002669:Child Welfare; D016001:Confidence Intervals; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007114:Immunization; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011058:Pollen / Q000009:adverse effects* / Q000276:immunology*; D015995:Prevalence; D012135:Respiratory Sounds; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D012423:Rural Health; D012572:School Health Services; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
D000393:Air Pollutants; D000485:Allergens