Background Posttraumatic olfactory dysfunction is a clinical challenge due to refractory characteristics and limited therapeutic options. Olfactory training has been proved to be effective for olfactory dysfunction with varied etiologies. We pooled existing studies to evaluate the effects of olfactory training in patients with posttraumatic olfactory dysfunction. Methods A systematic literature review using PubMed, Embase, Cochrane Library, and Web of Science was conducted to identify studies assessing olfactory change in patients with posttraumatic olfactory dysfunction after olfactory training. Results Of the initial 812 abstracts reviewed, 13 full‐text articles were included. Clinically significant results after olfactory training were defined as an improvement of threshold, discrimination, and identification (TDI) score ≥6 or University of Pennsylvania Smell Identification Test (UPSIT) score ≥4. Six studies were included in the meta‐analysis, 36.31% (95% confidence interval [CI], 0.28 to 0.45) of posttraumatic patients would achieve clinically significant results after olfactory training with a mean increase of TDI score of 4.61. Conclusion Olfactory training might be a promising modality for the treatment of posttraumatic olfactory dysfunction. More high‐quality studies with controls are needed to clarify the effect of olfactory training on total olfactory performance and subcomponents of olfaction.

Background: Postviral olfactory dysfunction (PVOD) is a clinical challenge due to limited therapeutic options and poor prognosis. Both steroids and olfactory training have been proved to be effective for olfactory dysfunction with varied etiologies. We sought to perform a systematic review to summarize the evidence of steroids or olfactory training for patients with PVOD.Methods: A systematic literature review using PubMed, Embase, Cochrane Library, and Web of Science was conducted to identify studies assessing olfactory change in patients with PVOD receiving steroid or olfactory training.Results: Of the initial 273 abstracts reviewed, 20 articles with data from 2,415 patients with PVOD were included. Treatments including topical steroids, systemic steroids, classical olfactory training (COT), modified olfactory training (MOT), and olfactory training with steroid were analyzed. Both psychophysical olfactory testing and subjective symptom scores were utilized to assess the olfactory function. The routine use of nasal steroid spray alone during the management of PVOD seems to have no positive effect on olfactory dysfunction. Direct injection of steroid or nasal steroid spray into the olfactory cleft significantly improved the olfactory function in patients with PVOD. Olfactory improvement is greater than that of the natural course of the disease with short-term COT. Patients with PVOD would benefit more from long-term COT (>12 weeks). Treatment duration, various odorants, olfactory training devices, changing the types of odors periodically, different molecular odorants, and different concentrations of odorants tended to increase the efficiency of MOT. Clinically significant improvement after olfactory training was defined as an increase of threshold, discrimination, and identification (TDI) score ≥6. From week 24 to week 36, both COT and MOT groups reached the maximum therapeutic effect regarding the number of participants achieving clinically significant improvement. A combination of local or oral steroids with olfactory training is more efficient than COT only.Conclusion: Olfactory function in patients with PVOD was effectively improved through direct steroid administration in the olfactory cleft, COT, or modification of COT. The addition of topical steroids to COT therapy showed a tendency for greater olfactory improvement in patients with PVOD.

Background Nasal sprays with corticosteroids deliver medication to the restricted areas including anterior and inferior parts of the nasal cavity. The fluticasone exhalation delivery system (EDS-FLU) has recently been proved to improve care by increasing superior/posterior intranasal corticosteroid deposition. Objective This study aims to evaluate the efficacy of EDS-FLU in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Methodology A systematic literature review using Pubmed, Embase, Cochrane Library, and Web of Science was conducted to identify studies assessing the effect of EDS-FLU on outcomes in patients with CRSwNP. Results Of the initial 108 abstracts reviewed, 4 full-text articles were included. The 22-item sinonasal outcome test scores were significantly decreased in patients with CRSwNP after receiving EDS-FLU twice a day (93, 186, or 372 μg) for 16 weeks when compared with exhalation delivery system (EDS)-placebo (all P < .001). Patients with CRSwNP reported significant improvement of smell after receiving twice daily EDS-FLU twice a day (93, or 372 μg) for 4 weeks when compared with EDS-placebo (all P < .05). The proportions of patients achieving ≥1-point improvement in total polyp grade were significantly higher in EDS-FLU group and dose dependent, with the highest rates in the 372 μg group. The proportions of patients achieving polyp elimination were significantly higher in EDS-FLU group with the highest rates in the 372 μg group. Conclusion This is the first systematic review of the clinical outcomes in patients with CRSwNP treated with EDS-FLU. EDS-FLU produced significant improvements regarding the quality of life, smell, and endoscopic assessment of polyp grade.