Purpose of the Study. To perform a meta-analysis of all published controlled studies concerning sublingual-swallow immunotherapy (SLIT) to determine rates of adverse events (AEs).
Study Population. Subjects were from 25 published studies (primarily European) aged 5 to 60 years (6 studies only enrolled children, 9 only adults, and the remainder a mix of both).
Methods. A systematic Medline review from 1986 to May 2004 was performed. Twenty-five published double-blind, placebo-controlled studies using SLIT that included efficacy and safety data were analyzed. Twelve studies used a high allergen dose (defined as 50–500 times the standard subcutaneous dose), and 13 used a low allergen dose (defined as 1–50 times the subcutaneous dose). AEs were defined as local or systemic: local included oral itching and/or swelling and gastrointestinal complaints, and systemic reactions included skin reactions and ocular, nasal, and chest symptoms. The rates of AEs were compared between the groups. The allergens used in the studies included mites, grasses, trees, and ragweed (single-allergen treatments).
Results. Combining the studies, there were a total of 445 subjects (405 placebo) in the high-allergen-dose group and 302 subjects (285 placebo) in the low-allergen-dose group. Children accounted for 103 total active-dose subjects. A total of 904 AEs were reported in the 198 553 active-allergen doses given, with 694 local reactions and 210 systemic reactions, with a rate of 0.15 to 0.2 reactions per patient. There were no reports of anaphylaxis. Overall, subjects in the low-allergen-dose group had significantly more local reactions than those in the high-dose group. However, there was no significant difference in the number of patients with AEs between the high- and low-allergen-dose groups when compared as a ratio of the number of SLIT doses received.
Conclusions. This analysis found that local reactions were common with SLIT but were mild and self-resolved. Systemic reactions occurred rarely and were not dose dependent. The authors conclude that SLIT is safe for use in adults and children.
Reviewer Comments. SLIT has been widely used in Europe in recent years, has been found to be efficacious by other studies, and has a good safety profile (supported by the meta-analysis). Another article in this same journal (Clin Exp Allergy. 2005;35:560–564) found SLIT to be safe in children younger than 5 years. SLIT is being studied in the United States as well and may be an option in the near future for treatment of allergic rhinitis.
- Copyright © 2006 by the American Academy of Pediatrics