Double-blind, placebo-controlled study of sublingual immunotherapy in patients with latex-induced urticaria: a 12-month study

Abstract

Natural rubber latex (NRL) allergy is a worldwide problem. Although prevention is sufficient to reduce sensitization, prolonged avoidance is needed to prevent resensitization or adverse reactions on re-exposure. This double-blind, placebo-controlled study was conducted to determine the efficacy of sublingual immunotherapy (SLIT) with latex. Forty patients with NRL allergy were enrolled. At diagnosis, 30 presented urticaria and 10 asthma. Patients were evaluated on their clinical history and an allergological assessment: skin prick test with latex extract, serum-specific IgE and provocation tests. Patients were subdivided by complaint (asthma or urticaria), and randomized to receive SLIT with latex extract (ALK-Abelló, Lainate, Milan, Italy) or placebo. The evaluable population consisted of 35 patients, 18 treated with SLIT and 17 with placebo. The results show that 12 months of SLIT improved the symptoms score and reduced the medication score in all subjects. The subjective evaluation was corroborated by improved bronchial and glove provocation test results. The latex-specific IgE levels increased slightly in the SLIT group, and skin sensitization was reduced at the end of the trial in all the patients treated with SLIT. The immunotherapy was not complicated by any severe adverse reactions. This is the first double-blind, placebo-controlled evaluation of the efficacy of SLIT with latex extract conducted in adult patients allergic to NRL. SLIT with latex can be proposed for subjects with latex allergy, especially those for whom complete avoidance of latex exposure may be very difficult or even impossible. More studies are needed to evaluate the efficacy of SLIT in the treatment of subjects with latex allergy who are sensitized to inhalant allergens.