The accuracy of features in the clinical history for predicting atopic sensitization to airborne allergens in children.

BACKGROUND

The clinical history is given considerable weight when one decides which allergens are responsible for a patient's symptoms, and in research studies the clinical history has been used as the "gold standard" with which different tests for allergy are compared.

OBJECTIVES

To determine whether standardized questions accurately predict replies to detailed questions asked by an experienced allergist, and to assess the utility of certain standardized questions for predicting sensitization to individual allergen groups.

METHODS

Trained interviewers put standardized questions to parents of 1160 children, aged 1 to 17 years, who had respiratory symptoms and had been newly referred to the allergy clinic of a children's hospital. For the first 151 of the subjects the answers were compared with those elicited by questions asked by a pediatric allergist. Skin prick tests and pollen counts were performed by a technologist.

RESULTS

The standardized questions had an accuracy for predicting the allergist's history of 93% to 97% for all questions except one. The standardized questions with the highest accuracy for predicting the skin test results to the appropriate allergens were the following: for mite, improvement in symptoms when outdoors (66.8%) and when in dry areas 69.4%), and aggravation during house cleaning (65.9%) and when bed making (70.6%); for dog, symptoms when with dogs (80.6%); for cat, symptoms when with cats (77.3%); for tree pollen, symptoms worse in April (70.8%) and when among trees in March and April (80.8%); and for grass pollen, exacerbation in June (69.2l%) and during lawn mowing (71.2%). Although specificity was generally above 80%, sensitivity was variable, ranging from 11% to 56%.

CONCLUSIONS

The standardized questions accurately predicted a detailed history obtained by an experienced allergist. Because standardized questions are reproducible they are the preferred method of history taking for research projects. Because several of the standardized questions have a high specificity they are useful for excluding sensitization to individual allergen groups, but because they have only a modest sensitivity, they are less helpful for detecting those who are sensitized to individual allergen groups.