Value of immunoglobulin E (IgE) in the private practice of allergy. Eight years experience: 1973-1981.

In private practice the majority of patients evaluated by allergists are truly atopic. To assess the clinical value of determining the serum level of immunoglobulin E (IgE) in such patients the records of an individual private allergist were reviewed and all new patients were evaluated. Over an eight year period 7,000 new patients were seen and 5,500 measurements of IgE were performed. An elevated serum IgE value was indicative of the atopic state with few false positives. Successful immunotherapy as determined by patient reports, the decreased use of medications and reduced clinical visits was correlated positively with a decrease in serum IgE levels. This was true regardless of the initial value of the IgE. Unsatisfactory results in immunotherapy were often accompanied by an increase in IgE levels. Serial determinations of serum IgE levels over several years of treatment are of value in the evaluation of allergic patients in private practice.