BACKGROUND Data on the prevalence of perennial versus seasonal allergic asthma in Italy are lacking; moreover, there is limited evidence on the effect of omalizumab on patient-reported outcomes in Italian patients with severe allergic asthma. PROXIMA, an observational, multicenter study, was designed to assess the prevalence of perennial versus seasonal allergic asthma (cross-sectional phase) and the effect of omalizumab on improving illness perception, quality of life (QoL) and asthma control of Italian patients with severe allergic asthma (longitudinal phase). METHODS The study included a cross-sectional phase (n = 357) and a longitudinal phase (n = 123): during the longitudinal phase, patients received omalizumab (75-600 mg subcutaneously every month) and were followed-up for 12 months. The primary parameter of cross-sectional phase was prevalence of perennial allergic asthma and that of longitudinal phase was proportion of patients with asthma control (assessed using asthma control questionnaire [ACQ]). Secondary parameters assessed were patients' disease perception, level of asthma control, exacerbation rate during both cross-sectional and longitudinal phases, and patients' compliance to and persistence with omalizumab, and patients' QoL during the longitudinal phase. RESULTS Most patients (95.8%) had perennial allergies; 81% had polysensitization. Of 99 patients in the per-protocol set, 95 (95.96% [95% CI: 89.98-98.89%]) achieved asthma control (ACQ < 4) at both 6 and 12 months of omalizumab treatment; ACQ score decreased after 6 and 12 months (P < 0.0001). Omalizumab treatment resulted in a significant improvement in QoL and patients' illness perception and 87% decrease in exacerbation rate. The compliance rate with omalizumab was high (73.2%). No new safety signals were identified during treatment. CONCLUSIONS This study demonstrated that in severe allergic asthma, omalizumab improves patient-reported outcomes such as patients' illness perception and QoL, while confirming improvement of asthma control and exacerbation rate reduction in Italian patients.