Respiratory allergy due to Alternaria is a relevant clinical problem, and specific immunotherapy may represent a viable treatment option. Sublingual immunotherapy (SLIT) is safe and effective, but data for Alternaria are lacking. The study is aimed at assessing the efficacy of a standardized SLIT in patients sensitised to Alternaria, in a randomized, double blind, placebo controlled fashion.

Patients with rhinitis with/without intermittent asthma, and ascertained allergy to Alternaria are enrolled. After a baseline season, SLIT or matched placebo are given for 10 months. Symptoms and rescue medication intake are recorded on diary cards from June to October. Skin prick test, specific IgE and IgG4 and precipitins are measured at baseline and at the end of the study. Alternaria spore count is also performed. Primary outcome is the change in symptom score in the active vs placebo group. Secondary outcomes: changes in rescue medication intake, alternaria specific IgE and IgG4, skin prick test reactivity.