Management of post-COVID olfactory disorder: is olfactory training effective on recovery of olfactory function?

Year 2022, , 42 - 50, 30.09.2022

Songül Demir , Bilal Sizer , Enes Sırma

https://doi.org/10.33204/mucosa.1174280

Abstract

Background The number of patients presenting with sudden onset and persistant anosmia and other olfactory disorders, which is a finding related to coronavirus disease has increased considerably.
Objective In this study, we aimed to evaluate the efficacy of olfactory training in patients with persistent anosmia after Covid-19 infection.
Methods Forty-six patients who applied for a sudden loss of smell after Covid-19 infection and still had olfactory disorders were included in the study. Odor threshold and odor identification tests were performed on the patients before the treatment. As olfactory training, four scent bottles included the following groups: phenyl ethyl alcohol, eucalyptol group, citronellal group and eugenol group were given to patients, and they were instructed to sniff the odors twice a day, for five seconds each, when they woke up in the morning and before they went to sleep and make a daily check that they applied the treatment. Patients who continued the training for 12 weeks were re-evaluated with the odor threshold test and odor identification test.
Results The pre-training mean olfactory threshold score of the patients was 1.65±1.74, and the post-training mean olfactory threshold score was 3.89±2.73. It was observed that the olfactory threshold scores increased significantly after the olfactory training (P<0.001). The pre-training mean odor identification score of the patients before olfactory training was 4.09±3.53 and the post-training mean odor identification score was 8.24±4.53. It was observed that odor identification scores increased significantly after olfactory training (P<0.001).
Conclusion The results of this study show that olfactory training can be an effective treatment method for olfactory loss after Covid-19.

Keywords

anosmia, odor threshold, olfactory disorder, covid-19, olfactory training

COVID sonrası koku alma bozukluğunun yönetimi: Koku alma eğitimi koku alma fonksiyonunun iyileşmesi üzerinde etkili mi?

Abstract

Arka plan COVID-19 hastalığına bağlı ani başlangıçlı anosmi ve diğer koku alma bozuklukları ile başvuran
hasta sayısı oldukça artmıştır.
Amaç Bu çalışmada Covid-19 enfeksiyonu sonrası inatçı anosmisi olan hastalarda koku alma eğitiminin
etkinliğini değerlendirmeyi amaçladık.
Yöntem Çalışmaya COVID-19 enfeksiyonu sonrası ani koku kaybı şikayeti ile başvuran ve koku alma
bozuklukları devam eden 46 hasta alındı. Tedavi öncesi hastalara koku eşiği ve koku tanımlama testleri
yapıldı. Koku eğitimi olarak hastalara fenil etil alkol, okaliptol grubu, sitronelal grubu ve öjenol grubu
olmak üzere 4 koku şişesi verilmiş ve hastalara sabah uyandıklarında kokuları günde iki kez 5’er saniye
olmak üzere koklamaları söylenmiştir. Hastaların sabah ve yatmadan önce tedaviyi uyguladıkları günlük
olarak kontrol edildi. Eğitime 12 hafta devam eden hastalar koku eşiği testi ve koku tanımlama testi ile
yeniden değerlendirildi.
Bulgular Hastaların eğitim öncesi ortalama koku eşik puanı 1.65±1.74, eğitim sonrası ortalama koku
eşiği puanı 3.89±2.73 idi. Olfaktör eşik puanlarının olfaktör eğitimden sonra anlamlı olarak arttığı görüldü
(P<0,001). Olfaktör eğitim öncesi hastaların eğitim öncesi ortalama koku tanıma puanı 4.09±3.53, eğitim
sonrası koku tanımlama puanı ortalama 8.24±4.53 idi. Koku eğitiminden sonra koku tanıma puanlarının
anlamlı olarak arttığı gözlendi (P<0,001).
Sonuç Bu çalışmanın sonuçları, koklama eğitiminin Covid-19 sonrası koku kaybı için etkili bir tedavi
yöntemi olabileceğini göstermektedir.

Keywords

anosmi, koku eşiği, koku alma bozukluğu, covid-19, koku alma eğitimi

References

• World Health Organization (WHO). Pneumonia of unknown cause China. Geneva: WHO 2020 (cited 2021 July 20).Available from: URL: https://www.who.int/csr/don/05-january-2020-pneumonia-ofunkowncause- china/ en/
• Fu L, Wang B, Yuan T, et al. Clinical characteristics of coronavirus disease 2019 (COVID-19) in China: a systematic review and meta-analysis. J Infect 2020;80:656-65.
• Chen N, Zhou M, Dong X, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 2020;395:507-13.
• Elibol E. Otolaryngological symptoms in COVID-19. Eur Arch Otorhinolaryngol 2021;278:1233-6. Rocke J, Hopkins C, Philpott C, Kumar N. Is loss of sense of smell a diagnostic marker in COVID-19: a systematic review and meta-analysis. Clin Otolaryngol 2020;45:914-22.
• Hopkins C, Surda P, Kumar N. Presentation of new onset anosmia during the COVID-19 pandemic. Rhinology 2020;58:295-8.
• Russell B, Moss C, Rigg A, Hopkins C, Papa S, Van Hemelrijck M. Anosmia and ageusia are emerging as symptoms in patients with COVID-19: What does the current evidence say? Ecancermedicalscience 2020;14:ed98.
• Soler ZM, Patel ZM, Turner JH, Holbrook EH. A primer on viral-associated olfactory loss in the era of COVID-19. Int Forum Allergy Rhinol 2020;10:814-20.
• Hummel T, Whitcroft KL, Andrews P, et al. Position paper on olfactory dysfunction. Rhinology 2017;56:1-30.
• Vaira LA, Salzano G, Fois AG, Piombino P, De Riu G. Potential pathogenesis of ageusia and anosmia in COVID-19 patients. Int Forum Allergy Rhinol 2020;10:1103-4.
• Butowt R, Bilinska K. SARS-CoV-2: olfaction, brain infection, and the urgent need for clinical samples allowing earlier virus detection. ACS Chem Neurosci 2020;11:1200-3.
• Hummel T, Heilmann S, Huttenbriuk KB. Lipoic acid in the treatment of smell dysfunction following viral infection of the upper respiratory tract. Laryngoscope 2002;112:2076-80.
• Heilmann S, Huettenbrink KB, Hummel T. Local and systemic administration of corticosteroids in the treatment of olfactory loss. Am J Rhinol 2004;18:29-33.
• Addison AB, Wong B, Ahmed T, et al. Clinical Olfactory Working Group consensus statement on the treatment of post infectious olfactory dysfunction. J Allergy Clin Immunol 2021;147:1704-19.
• Hopkins C, Alanin M, Philpott C, et al. Management of new onset loss of sense of smell during the COVID-19 pandemic - BRS Consensus Guidelines. Clin Otolaryngol 2021;46:16-22.
• Huart C, Philpott CM, Altundag A, et al. Systemic corticosteroids in coronavirus disease 2019 (COVID-19)-related smell dysfunction: an international view. Int Forum Allergy Rhinol 2021;11:1041-6. Whitcroft KL, Hummel T. Olfactory Dysfunction in COVID-19: Diagnosis and Management. JAMA 2020;323:2512-4.
• Demir S, Sizer B, Gul A, Topcu I. Culturally modified olfactory test adapted to East-Turkey: A comparison with Sniffin’ Sticks. Int J Clin Pract 2021;75:e14458.
• Gul A, Yilmaz B, Karababa S, Tuna SF, Ozkurt FE, Topcu I. Evaluation of smell function changes in pregnancy. Kulak Burun Bogaz Ihtisas Dergisi 2015; 25:92-6.
• Henning H. Die qualitatenreihe des geschmacks (The quality series of taste). Zeitschrift Psychologie 1916;74:203-19.
• Lechien JR, Chiesa-Estomba CM, Beckers E, et al. Prevalence and 6-month recovery of olfactory dysfunction: a multicentre study of 1363 COVID-19 patients. J Int Med 2021;290:451-61. Stogbauer J, Wirkner K, Engel C, et al. Prevalence and risk factors of smell dysfunction-a comparison between five German population-based studies. Rhinology 2020;58:184-91. Hummel T, Rissom K, Reden J, Hahner A, Weidenbecher M, Huttenbrink KB. Effects of olfactory training in patients with olfactory loss. Laryngoscope 2009;119:496-9.
• Konstantinidis I, Tsakiropoulou E, Bekiaridou P, Kazantzidou C, Constantinidis J. Use of olfactory training in post-traumatic and postinfectious olfactory dysfunction. Laryngoscope 2013;123:E85-E90.
• Geibler K, Reimann H, Gudziol H, Bitter T, Guntinas-Lichius O. Olfactory training for patients with olfactory loss after upper respiratory tract infections. Eur Arch Otorhinolaryngol 2014;271:1557-62.
• Damm M, Pikart LK, Reimann H, et al. Olfactory training is helpful in postinfectious olfactory loss: a randomized, controlled, multicenter study. Laryngoscope 2014;124:826-31.
• Pekala K, Chandra RK, Turner JH. Efficacy of olfactory training in patients with olfactory loss: a systematic review and meta-analysis. Int Forum Allergy Rhinol 2016;6:299-307.
• Altundag A, Cayonu M, Kayabasoglu G, et al. Modified olfactory training in patients with postinfectious olfactory loss. Laryngoscope 2015;125:1763-6.
• Kattar N, Do TM, Unis GD, Migneron MR, Thomas AJ, McCoul ED. Olfactory training for postviral olfactory dysfunction: systematic review and meta-analysis. Otolaryngol Head Neck Surg 2021;164:244-54.
• Chiesa-Estomba CM, Lechien JR, Radulesco T, Michel J, Sowerby LJ, Hopkins C, Saussez S. Patterns of smell recovery in 751 patients affected by the COVID-19 outbreak. Eur J Neurol 2020; 27:2318-21.
• Kandemirli SG, Altundag A, Yildirim D, Sanli DET, Saatci O. Olfactory bulb MRI and paranasal sinus CT findings in persistent COVID-19 anosmia. Acad Radiol 2021;28:28-35.
• Gudziol V, Buschhuter D, Abolmaali N, Gerber J, Rombaux P, Hummel T. Increasing olfactory bulb volume due to treatment of chronic rhinosinusitis--a longitudinal study. Brain 2009;132:3096-101.
• Altundag A, Yilmaz E, Kesimli MC. Modified olfactory training is an effective treatment method for COVID-19 induced parosmia. Laryngoscope 2022;132:1433-8. Lechner M, Liu J, Counsell N, et al. The COVANOS trial–insight into post-COVID olfactory dysfunction and the role of smell training. Rhinology 2022 Jul 28. doi:10.4193/Rhin21.470.