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

604

INTERNATIONAL CONSENSUS ON OLFACTION

TABLE IX.34 Use of vitamin A to treat OD Study Year LOE Study design

Study groups

Clinical end point Conclusions

Subjective olfactory improvement

Improvement in odor detection in 50 of 56 patients

Patients with olfactory disorders (eg, postinfectious, posttraumatic, idiopathic; n = 56) treated with high-dose systemic vitamin A therapy (injection, tablets, oral emulsion; 50,000 to 150,000 IU/day) for up to 12weeks Vitamin A–deficient patients (n = 27) treated with oral vitamin A (10,000 μ g/day) for 4weeks Patients with postinfectious or posttraumatic olfactory disorder (n = 52) receiving either oral vitamin A at a dose of 10,000 IU/day or placebo for 3 months Patients with acne (n = 33) treated with oral

Duncan and

1962 4

Case series over a

period of 15 years with differences in interventions

Briggs 1570

Garrett

1984 4

Descriptive

Pyridine detection and recognition threshold improvement

Significant improvement in olfactory threshold

Laster et al 1510

(noncontrolled)

SS-TDI

No significant difference between placebo and verum groups regarding the TDI change and subfunction (TDI) change after treatment

Reden

2012 2

Double-blind,

et al 456

improvement

placebo-controlled, randomized clinical

Kartal

2017 4

Descriptive

Improvement in SS-ID

Significant improvement in odor identification

et al 1571

(noncontrolled)

isotretinoin (0.5 to 0.8 mg/kg per day) for 3 months

Improvement in SS-TDI

OT + vitamin A produced significantly greater improvement compared with training alone, in discrimination score for all patients and in threshold and

Hummel et al 1572

2017 4

Retrospective cohort Patients with postinfectious (n = 102) or posttraumatic (n = 68) olfactory disorder (n = 170)

Treated with topical vitamin A 10,000 IU once daily, for 8 weeks and performing OT for 12 weeks Performing OT for 12 weeks only

discrimination in the postinfectious group

In the postinfectious group, significantly more patients showed improved general OF with combined therapy compared with training alone LOE level of evidence; OD = olfactory dysfunction; OF = olfactory function; OT = olfactory training; SS-ID = Sniffin’ Sticks identification only; SS-TDI = Sniffin’ Sticks threshold, discrimination, identification combination; TDI = threshold, discrimination, and identification.

reported that the improvement rate in patients with post– upper respiratory tract infection dysfunction, who received treatment with intranasal steroid treatment alone, TSS oral administration alone, or a combination of steroids and TSS, for 3 months, was 29%, 55%, and 60%, respectively. Most recently, Ogawa et al 1326 additionally reported on the time-course of olfactory recovery and the prognostic fac tors in patients with PIOD treated with TSS. They revealed that the recovery of OF often occurred during the early period, < 6 months from symptom onset, but the number of patients with recovery of OF increased for long-term symp toms 24 months after the first visit. This study also reported

that residual OF and younger age were prognostic factors for recovery of OF. 1326 Unfortunately, all of these studies are case series, with no placebo-control group and no tim ing restriction for enrollment, and therefore the potential for spontaneous resolution or other biases to confound these findings make these data currently inconclusive. Use of TSS for the treatment of OD Aggregate grade of evidence : C (Level 4: four studies). Benefit : Objective olfactory tests revealed the improve ment of OF by oral TSS administration. Lack of consid eration for spontaneous improvements, lack of control