PREVIOUS STUDIES have suggested that certain states of hypersensitivity may be causally related to leukemia and lymphoma.1-5 This report is an epidemiologic evaluation of allergic and rheumatic conditions appearing in a relatively large collection of histories of leukemic children and their close relatives.
Data were obtained by a review of records from the National Cooperative Leukemia Survey, in which 12 medical centers participated. The Survey was conducted by interviewing the parents of 498 leukemic children under 16 years of age and the parents of neighborhood controls matched by age, birth order, family size, and race. The diagnoses of leukemia were made between 1958 and 1961 by well-qualified hematologists at the participating centers. The present study is based on replies to questions regarding the presence of allergic and rheumatic conditions in each family member and on pertinent information concerning hospitalizations and x-ray examinations. The conditions recorded were restricted to those