Randomized, double-blind, placebo-controlled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients

INTERVENTION: Sublingual immunotherapy (SLIT) to latex (SLIT latex, ALK‐Abello, Madrid, Spain). The SLIT is oral fluid. The treatment was administered once a day: two drops of SLIT each day. The study was performed in two phases: the first one, double‐blind, placebo‐controlled during one year; and the second one, also for one year, opened, where every patient received active treatment. CONDITION: Latex allergy PRIMARY OUTCOME: Size of wheal in skin prick test measured by parallel lines assay SECONDARY OUTCOME: Basophil Activation Test. Conjunctival challenge test. ; The difference in the concentration of latex extract needed to obtain 5 points of symptoms in the conjunctival challenge test was compared between placebo and active groups after one year of active treatment and intragroup after one and two years of treatment. Glove use test. ; The difference in the time using the latex glove needed to obtain 5 points of symptoms in the glove used test was compared between placebo and active groups after one year of active treatment and intragroups after one and two years of treatment. Specific IgE determination. ; Specific IgE to NRL was measured using commercial uniCAP (Phadia, Sweden) to NRL (k81), and to recombinant main allergenic components of latex (Hev b 1, hev b 3, hev b 5, Hev b 6, and Hev b 8). The results were compared between placebo and active groups after one year of active treatment and intragroups after one and two years of treatment. INCLUSION CRITERIA: Inclusion criteria comprised a clinical history of natural rubber latex allergy (documenting the usual symptoms of urticaria, angioedema, rhinitis, conjunctivitis, asthma or anaphylaxis) or a positive response to the gloves use test and/or conjunctival test plus positive prick test to NRL (wheal greater than or equal to 3x3 mm).