IMMUNOTHERAPY - A ONE-YEAR PROSPECTIVE-STUDY TO EVALUATE RISK-FACTORSOF SYSTEMIC REACTIONS

Background: We did a prospective study in Atlanta, Georgia, during 199 1 on the rate of systemic reactions caused by immunotherapy in a clini c that uses aqueous allergen extracts, Methods: Immunotherapy reaction s were monitored. Symptoms were recorded with respect to time of onset , involvement of respiratory tract or skin, and presence of hypotensio n. Results: There were 98 systemic reactions in 96 patients (1 per 160 0 visits or 1 per 47 patients). There was no direct relationship to se asonal pollen counts. There was, however; a correlation with the Augus t to October increase in mold counts. There was no correlation between reactions and the age of the patient or the age of the extract patien ts were more likely to experience a reaction during the buildup phase than during maintenance therapy. The time of onset and the severity of the reaction were in agreement with previous reports. Severe reaction s that included hypotension all occurred less than 30 minutes after th e injection. In contrast to previous reports, patients with asthma wer e not at higher risk for a systemic reaction. Conclusion: Immunotherap y has a significant but low rate of systemic reaction. Potentially ser ious reactions may be mitigated by taking extra precautions during the earlier phases of an immunotherapy program and during seasons when mo ld counts are high.