Specific immunotherapy with a standardized latex extract versus placebo inallergic healthcare workers

Background: The prevalence of allergy to natural rubber latex proteins has increased over recent years among healthcare professionals but also in chil dren undergoing multiple operations. Exposure to the antigen mainly occurs through the respiratory mucosa and the percutaneous route. Clinical manifes tations range from urticaria to angioedema, rhinoconjunctivitis, bronchial asthma, or anaphylactic shock. Preventive measures have been proposed to re duce the risk of sensitization by using only powder-free or synthetic glove s and latex-free material in operating units, but this is not always possib le. Objective: The aim of this study was to investigate the efficacy and safety of specific immunotherapy in sensitized workers. Methods: Seventeen patients with latex skin allergy and rhinitis (9 of whom also had asthma) were included in this randomized, double-blind, placebo-c ontrolled trial (9 in the active group and 8 in the placebo group) for 1 ye ar. Treatment started with a 2-day course of rush immunotherapy in hospital . Treatment efficacy was assessed after 6 and 12 months by means of symptom and medication scores recorded on diary cards. Conjunctival provocation te sts were also performed. Results: Patients in the active treatment group had a significantly tower t otal rhinitis score after 6 (P < .04) and 12 months (P < .05), conjunctivit is score after 6 months (P < .02), and cutaneous score after 12 months (P < .03) than in the placebo group, Asthma symptoms after 6 or 12 months of tr eatment were not significantly different between the two groups after adjus tment for baseline values. The global medication score was markedly decreas ed in the latex-treated group. A significant difference in conjunctival rea ctivity was observed in favor of the active group: the number of patients f or whom the threshold dose was increased after 12 months of treatment was s ignificantly greater in the active group than in the placebo group (P < .02 ). Most injections were well tolerated, but several adverse effects, includ ing hypotension, urticaria, wheezing, and pharyngeal edema, were observed. Conclusion: The clinical benefits observed during the present study include d a significant improvement of rhinitis, conjunctivitis, and cutaneous symp toms. Immunotherapy also decreased allergen-specific conjunctival reactivit y. Latex-specific immunotherapy may allow sensitized personnel to remain at work, but further trials need to be conducted in a larger number of patien ts.