Sublingual Immunotherapy (SLIT) is a viable alternative to conventional immunotherapy, but some concerns exist about the adherence to SLIT, and few experimental data exist about this topic. We aimed at quantifying the adherence to the SLIT in patients with mite allergy.

We performed a multicenter study (INSIT) to assess the adherence, given as allergoid SLIT in tablets (Lais, Lofarma, Italy), in patients with mite allergy. Patients underwent random telephonic interviews, during which they were asked to immediately count the remaining tablets. The adherence was measured by assessing the reported number of remaining tablets versus that expected, based on the administration schedule. Demographic and socio-economic data and clinical scores were also recorded.

Forty-one patients (16 male: 15-65 yrs, mean age: 36.3), 19 with rhino-conjunctivitis and 22 with concomitant asthma were enrolled in the first year of the study. Allergoid SLIT was given continuously and the compliance was assessed at the end of 1 year of treatment. There were two dropouts: one lack of efficacy, one onset of nasal polyps. In the remaining 39 patients, the adherence was 3.929/4.056 tablets (96.8%). Sporadically omitted doses (less than 1 tablet/month) were reported by 6 patients (14.6%). No systemic or local side-effects were reported. We also observed a statistically significant improvement of rhinoconjunctivitis and asthma symptoms score and medication consumption. The compliance was in general lower in patients frequently travelling for business reasons.

The preliminary results of this ongoing study show that the adherence to allergoid SLIT is satisfactory, despite it is self-administered.