Sublingual immunotherapy in asthma and rhinoconjunctivitis; systematic review of paediatric literature.

AIMS To evaluate the clinical efficacy of sublingual immunotherapy (SLIT) in respiratory allergy in children. METHODS A systematic literature review was conducted. The search was focused on all the double blind (and double dummy if necessary) studies. SEARCH STRATEGY Medline, Embase, Cochrane Controlled Trial Register, Abstract of Cochrane Airways Group, hand search, and archives of some SLIT producers. All the selected studies were assessed and evaluated for quality in a standardised independent way. RESULTS Eight randomised, double blind, placebo controlled studies on SLIT were selected. Five studies were run with house dust mite (HDM), one with olive pollen, one with wall pellitory (Parietaria) pollen, and one with grass pollen. A quantitative evaluation of the studies was not possible because the outcomes and the results of single studies were presented according to different criteria. Therefore only qualitative analysis was performed. No clinically relevant results were shown, independently from statistical significance, in the use of SLIT for respiratory allergies due to seasonal allergens (olive, wall pellitory, and grass pollens) and, on the whole, for rhinoconjunctivitis due to HDM in children. For mild to moderate persistent asthma due to HDM, statistically significant and low to moderate relevant clinical effects were observed. CONCLUSIONS SLIT can be currently considered to have low to moderate clinical efficacy in children of at least 4 years of age, monosensitised to HDM, and suffering from mild to moderate persistent asthma. This benefit seems to be adjunctive with respect to the environmental preventive measures against HDM.