Purpose of this study was to assess the tolerability of the allergoid sublingual immunotherapy (SLIT) performed with a monomeric allergoid (Lais, Lofarma, Italy).

We selected 183 patients (101M/82F, age: 9-47 years, mean age: 27 years), allergic to Mites (88), Grass (82), Parietaria (8), and Corylaceae/Betulaceae (5), suffering either from rhinitis (152) or asthma (5) or asthma and rhinitis (26). All patients or their parents were instructed to keep a diary for the daily evaluation of any local and/or systemic side effect related to the SLIT administration. Patients were authorised to use rescue drugs to control allergy symptoms, if necessary. All patients were treated with the allergoid SLIT in tablets for two years, according to the schedule suggested.

No adverse reaction were observed in 173 out of 183 patient (94,5%). Ten patients (5,4%) showed side effects, consisting in 1 intense pharyngeal edema and itching, successfully managed by rescue medication, 5 mild local itching of the mouth, 1 mild abdominal pain and 3 intercurrent flu-like episodes, not related to allergoid SLIT. No adverse events occurred when the allergoid SLIT was re-administered, thus reaching the maintenance dose in all patients but one child.

Allergoid SLIT is generally well tolerated in more than 90% of the treated patients.