xRead - Olfactory Disorders (September 2023)

20426984, 2022, 4, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/alr.22929, Wiley Online Library on [04/09/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

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INTERNATIONAL CONSENSUS ON OLFACTION

Value judgments : Autoimmune diseases can cause OD, and treatment of the underlying disease process may help correct both OD as well as other associated symptoms. Policy level : Evaluating and treating patients with olfactory disorders related to suspected or known autoim mune diseases is recommended. Intervention : Laboratory tests, including serum autoimmune markers should be considered in individuals with OD and suspected underlying autoimmune disease. F If no underlying disease state to correct 1 Treatment with corticosteroids The evidence for steroids, both topical and systemic, as treatment for nonsinonasal disease–related olfactory loss is limited, as recently highlighted in a systematic review. 1517 While excluding rhinosinusitis and rhinitis, the causes of these olfactory losses remain heterogeneous and include postinfectious, posttraumatic, and idiopathic causes. Base line severity of OD is varied among patients and stud ies ranging from mild hyposmia to functional anosmia, and differing olfactory measurements make it difficult to directly compare studies. Five studies investigated the use of topical steroids in nonsinonasal disease olfactory loss (Table IX-25). In three uncontrolled cohort studies (Level 4), 20% (23 of 117 patients) demonstrated clinically significant improvement in olfactory measures using topical steroid sprays. 1518–1520 However, a small RCT found no olfactory benefit from the addition of topical steroid sprays (fluticasone) in patients who were previously responsive to oral steroids. 1521 Cur rently, there are no strong data supporting the use of topical steroid sprays. However, one RCT demonstrated efficacy with the use of topical steroid irrigations in the treatment of nonsinonasal inflammatory-related olfactory loss. Indi viduals using twice-daily budesonide nasal rinses along with OT were more likely to achieve clinically significant improvement compared with saline rinses with OT (43.9% versus 26.9%, P = 0.039). 1522 Additional RCTs would be use ful to corroborate this finding. There is a paucity of studies evaluating the optimal head position for topical steroid delivery to the OC, with most utilizing cadaveric models (Table IX-26). Two stud ies reported successful irrigation delivery to the OE using the head-over-sink position. 1523,1524 Even in maximal post surgical conditions (modified Lothrop), topical rinses had superior OC penetration compared with topical sprays. 1524 Other head positions (head-tilted forward, vertex-to-floor, neutral position, head reclined, and lateral head low) have demonstrated variable success in topical delivery. 1523–1531

Middle turbinate resection failed to improve delivery of irrigation to the olfactory mucosa. 1532 Thus, the volume of rinses appears to be important in accessing the olfactory mucosa and may explain why nasal steroid rinses but not sprays are beneficial in treatment of nonsinonasal disease OD. Meanwhile, the use of systemic steroids alone in nonsi nonasal disease–related anosmia remains equivocal with only weak evidence favoring its use (Tables IX-27,28). The most commonly used corticosteroid was oral prednisolone with a starting dose of 30 to 60 mg/day and a 2-week taper. Five cohort studies with a total of 553 patients demon strated that 16.4% to 49.6% of patients treated with sys temic steroids had a significant improvement in olfaction threshold measurements 1353,1518,1533–1535 with two studies demonstrating clinically meaningful improvements of TDI in 12% to 29% of patients. 1518,1535 Systemic steroids were not beneficial in a small retrospective case series of patients who were nonrespondent to topical therapy 1426 and an RCT of patients with PTOD, although this study may have been underpowered. 1350 Systemic steroids appear to have an additive benefit when used in conjunction with top ical steroids. 1536 Three retrospective studies totaling 554 patients reported improved OF in patients receiving sys temic and topical steroids compared with topical steroid sprays alone. 1352,1537,937 For most of these studies, inclu sion of patients early ( < 6 months) into the course of olfac tory loss may allow for spontaneous recovery to confound their results. Notably, no adverse effects were reported in any these studies, although the potential risks of systemic corticosteroids given even in short bursts have been well documented. 1538 Overall, the literature supporting the use of steroids in nonsinonasal inflammatory causes of anosmia is lim ited with few RCTs. Topical steroid sprays are not rec ommended given their general lack of efficacy and lim ited delivery to the OC. Topical steroid rinses are rec ommended, with one high LOE study showing benefit with a minimal side-effect profile. Oral steroids remain an option with only weak evidence supporting their effi cacy, against which treatment risks must be considered and balanced. With both therapeutics, additional large scale RCTs are required to further elucidate their effi cacy, dosage, and timing in the treatment of nonsinonasal disease OD. The use of steroids to treat OD is not related to underlying inflammatory sinonasal disease Aggregate grade of evidence : C (Level 2: four studies; Level 3: one study; Level 4: 17 studies; Level 5: five studies). Benefit : Use of budesonide irrigations and systemic steroids may improve anosmia secondary to nonsinonasal inflammatory causes of OD.