Specific immunotherapy with a standardized latex extract in allergic workers:: A double-blind, placebo-controlled study

Background: Preventive measures have been proposed to reduce the risk of sensitization to natural rubber latex (NRL), but this is not always feasible. Objective: The aim of this study was to determine the efficacy and safety of specific immunotherapy with a standardized latex extract in sensitized workers. Methods: Twenty-four patients allergic to NRL with contact urticaria (n = 8) and rhinitis or asthma (n = 16) were included (16 in the active group and 8 in the placebo group). Treatment started in a cluster immunotherapy protocol, with injections every week for 3 months and then every other week for another 3 months. Results: Patients in the active group had significantly lower values than patients in the placebo group in skin terms of reactivity to NRL (P < .01), rubbing test results (P = .047), and latex glove use test results (P = .046) after 6 months of treatment. There were no significant differences between the active and placebo groups in symptom scores, use of medication, self-assessment, or methacholine test results either before or after treatment. Differences in nasal and bronchial symptoms during specific inhalation challenges (P = not significant and P = .05, respectively) were observed in favor of the active group. In the. active group 32 systemic reactions were observed (8% of doses), mostly during the build-up period, being more frequent in patients with respiratory symptoms (P = .004). All reactions responded promptly to treatment. Conclusion: Clinical efficacy was shown mainly on cutaneous symptoms, although an improvement in rhinitis and asthma symptoms was also observed during specific inhalation challenges. Latex-specific immunotherapy might be a useful approach for the treatment of latex allergy in sensitized workers.