A prospective controlled evaluation of winterized Pistacia lentiscus oil nasal spray in vasomotor rhinitis

Background Vasomotor rhinitis (VMR), currently included within the broader spectrum of non-allergic rhinopathy, is a chronic condition characterized by nasal obstruction, rhinorrhea, and hyperreactivity to non-specific environmental triggers. Although traditionally considered a neurovascular disorder driven by autonomic dysregulation, emerging evidence suggests that mucosal inflammatory and microbial factors may contribute to symptom persistence in selected patients. Winterized Pistacia lentiscus oil has demonstrated antimicrobial and anti-biofilm properties in upper airway experimental models, suggesting potential therapeutic relevance in chronic nasal disorders. Methods This prospective controlled study evaluated the effectiveness of a nasal spray medical device containing winterized Pistacia lentiscus oil (Bactorinol® nasal spray, PharmExtracta S.p.A., Italy) in patients with VMR. A total of 120 participants were enrolled, with 110 completing the study (58 treated, 52 controls). Primary endpoints included changes in Peak Nasal Inspiratory Flow (PNIF) and symptom burden assessed using the Sino-Nasal Outcome Test (SNOT-22). Secondary endpoints included nasal cytological assessment of inflammatory cellularity (neutrophils, eosinophils, mast cells), bacterial abundance, supranuclear stria, and cytological findings compatible with biofilm-like structures. Repeated-measures General Linear Models were used to evaluate treatment effects over time. Results Compared with controls, treated patients demonstrated significantly greater clinical improvement over the study period. SNOT-22 scores decreased by 30.5% in the treatment group versus 9.7% in controls (time × group interaction, p < 0.001). PNIF improved by 44.5% in treated subjects compared with 20.8% in controls ( p = 0.006 for interaction). Significant treatment-associated reductions were also observed for neutrophils ( p = 0.001), mast cells ( p = 0.021), bacterial abundance ( p = 0.002), and cytological findings compatible with biofilm-like structures ( p = 0.001). Although the treatment group presented a higher baseline burden for several parameters, post-treatment outcomes favored the intervention group. Conclusions Winterized Pistacia lentiscus oil nasal spray was associated with significant improvements in symptoms, nasal airflow, inflammatory cytology, and microbial-related cytological findings in patients with VMR. These findings support the hypothesis that selected phenotypes of non-allergic nasal disease may involve mucosal inflammatory and microbial components beyond classical neurovascular dysfunction. Larger randomized studies with microbiological and molecular characterization are warranted to confirm these preliminary findings and clarify mechanisms of action.