DANISH MEDICAL JOURNAL Patients and experiences from the first Danish flavour clinic Alexander Fjaeldstad1, 2, 3, Jelena Stankovic2, Mine Onat2, Dovile Stankevice1 & Therese Ovesen1, 2 ABSTRACT duced sense of smell (hyposmia) [1, 2], making olfac­ INTRODUCTION: Chemosensory dysfunction is common. tory dysfunction a very common disorder. Apart from ORIGINAL ARTICLE Although patients complain of taste loss, the most common these quantitative olfactory disorders, olfactory dis­ 1) Flavour Clinic, Ear cause of a diminished taste experience is olfactory orders can have a qualitative nature where stimuli are Nose and Throat dysfunction. Department, Holstebro distorted (parosmia) or emerge without apparent stim­ Regional Hospital, METHODS: Since January 2017, patients with complaints ulation (phantosmia). Around 10% of patients with dis­ Denmark about smell and/or taste loss have been referred to the torted flavour perception have an actual taste disorder, 2) Flavour Institute, Flavour Clinic by ear, nose and throat (ENT) practitioners. Prior while only a few percent have isolated taste disorders. Department of Clinical to referral, CT, endoscopy of the nasal cavity and allergy Medicine, Aarhus These include loss of taste (ageusia), reduced sense of testing were required. Patients underwent full olfactory and University, Denmark taste (hypogeusia) or distorted sense of taste (parageu­ 3) Hedonia Research gustatory testing, complete ENT and neurological examination sia). Group, Department of and review of medicine and medical history. Patients also In all cases, the sensory loss can cause a wide range Psychiatry, University of completed different questionnaires such as the Mini Mental Oxford, United Kingdom of complications and consequences for patients. Status Examination, the Sino-Nasal Outcome Test and the Patients often complain of a reduced quality of life due Major Depression Inventory. Dan Med J to limited enjoyment of food and exclusion from social 2020;67(4):A09190495 RESULTS: Among 515 patients, 97% complained of olfactory loss and 82% complained of taste loss. While 89% had a interactions involving food and beverages. This may measurable olfactory deficit, only 22% were found to have a impair appetite and dietary composition. For olfactory gustatory deficit. disorders, social seclusion may occur due to fear of CONCLUSIONS: An accurate distinction between smell and bodily malodours. Furthermore, olfactory cues of dan­ taste requires application of validated chemosensory tests ger such as gas, smoke or spoiled foods can cause haz­ and specialised knowledge. As this is not readily available in ards. In sum, a sensory deficit can severely impair many all ENT clinics, sensory loss without a clear aetiology should aspects of life, and olfactory loss can substantially in­ be referred to a more specialised centre. crease the risk of depression [3]. FUNDING: none. Compared with other senses, smell and taste dis­ TRIAL REGISTRATION: not relevant. orders have been a reclusive matter, for patients and clinicians alike. However, this is changing as special­ ised taste and smell clinics have emerged across the US For most people, the sensory experience of eating and and Europe in conjunction with emerging anosmia pa­ the ability to sense odours in our environment are an tient groups and social media networks. unsung part of daily routines. Fragments of attention The majority of olfactory and gustatory disorders are ignited when we are startled by encounters with are peripheral or mucosal in aetiology [4], why examin­ certain odours, hedonic gastronomic experiences, or ation, diagnostics and specialised clinics are generally the lack of stimulation during a common cold. More established within the ear, nose and throat (ENT) speci­ than 70% of the sensory experience of food is estimated ality. In Denmark, the ENT specialist practitioners are to derive from the olfactory stimulation of aromas, included in the public free healthcare system and no re­ which reduces the overall tasting experience to a uni­ ferral is needed. Here, assessment of common causes of form flat experience following a loss of the olfactory olfactory loss (e.g., chronic rhinosinusitis and allergy) sense. Smell is initially perceived through the nostrils is commonly diagnosed and treated in accordance with (orthonasal smell); however, during food consump­ established guidelines. However, when the aetiology tion, aromas from the food enter the nose through the was not clear, no further steps of structured diagnostics pharynx (retronasal smell). The integrated perception were available until 2016. of taste and retronasal stimuli in the conscious tasting Although many patients suffered from smell and experience explains why many patients with olfactory taste loss, no specialised clinic or national guidelines disorders initially complain of taste loss. existed. In 2016, the head of the ENT department, At least 1% of the population is estimated to have a Region Hospital West Jutland, Denmark, decided to es­ complete loss of smell (anosmia) and 15% have a re­ tablish a clinical work­up for patients suffering from Dan Med J 67/4 / April 2020 1 DANISH MEDICAL JOURNAL smell and taste disorders on request from the Flavour Initially, one examination room in the outpatient Institute. The aim of this manuscript is to describe the clinic was reserved per week for patients from all parts start­up of the first flavour clinic and to describe the de­ of Denmark. An ENT physician and a nurse trained in mographics and sensory deficits of the initial ≥ 500 fla­ performing the various smell and taste tests were re­ vour patients in order to provide knowledge needed to sponsible for the work­up programme. create a data­driven national guideline for diagnosing The official opening of the smell and taste clinic (the of smell and taste loss. Flavour Clinic) was held in December 2016. The first patients were received in January and February 2017 – METHODS a pilot study period to obtain knowledge about the fea­ Setting up the flavour clinic sibility of the work­up programme and time consump­ A prerequisite for accurate diagnostics of sensory dis­ tion. The average time used per patient was two hours, orders is validated taste and smell tests, and sufficient and all patients were able to participate in all tests. As knowledge of cut­off values for diagnosing a sensory the Department had received no financial support from loss. Thus, normative data on the smell and taste func­ the Flavour Clinic, the Healthcare Classification System tion in the Danish population had previously been col­ (“SKS”) and the Diagnosis Related Groups (DRG) codes lected in studies conducted by the Flavour Institute [5­ for the work­up programme were applied at the Danish 8]. Criteria for referral were based on advice from the Health Authority. Approval was achieved towards the leading German taste and smell clinic in Dresden and end of 2017. In December 2018, the Central Denmark an assessment of our initial experiences with Danish Region approved the ENT Department’s financing of the flavour patients. These criteria were published on the clinic by DRG means. Up to this point, patients had been Department’s website: only ENT specialists could refer followed up by telephone calls only due to a lack of re­ patients with subjective complaints about smell and/or sources for a clinical visit. Furthermore, the number of taste dysfunction, and endoscopy of the nasal cavity referrals had stabilised at approximately 420 annual pa­ was required prior to referral along with allergy testing tients. Based on this information, the future dimensions and CT of the nose and sinuses (adults only) to identify of the Flavour Clinic were settled, and follow­-up visits treatable sino­nasal causes, see Figure 1. were included to document the effects of various treat­ ment modalities. Diagnostic workflow Diagnostic pipeline for patients with smell and taste disorders. FIGURE 1 / The diagnostic workup in the Flavour Clinic consisted of the following: a questionnaire of taste and smell Identify the nature of flavour affection from symptoms, the Sino­Nasal Outcome Test 22 (SNOT­22) history, symptoms, and olfactory & gustatory screening questionnaire, the Major Depression Inventory (MDI) test, the Mini­Mental State Examination (MMSE), a complete list of medicine (current and prior), physical ENT examination including endoscopy with focus on Olfactory deficit (95%) Gustatory deficit (5%) the olfactory cleft and relevant (oto)neurological ex­ amination, Sniffin’ Sticks olfactory threshold, discrimi­ ENT examination ENT examination nation and identification (TDI) test for olfaction and a Endoscopy: rhinosinusitis Oral examination incl. saliva taste strip test for gustation. Subsequently, the taste Allergy testing Endoscopy: laryngeal strip test was replaced by a taste spray screening and CT: FESS protocol Ear examination the taste drop test, as a comparative study had demon­ Medication strated superior validity of the taste drop test [8]. Ol­ factometry and electro­gustometry were reserved for Aetiology uncertain Aetiology found medico­legal cases. For any MDI score of ≥ 26, referral Normal Aetiology found: for assessment of depression was discussed – and refer­ examination treat cause ral was recommended for a score of ≥ 31 [9]. For a Refer to Flavour Treat cause if pos- MMSE score of ≤ 24, further cognitive assessment was Clinic if no neurolo- sible generally recommended [10]. gical Explain mechanism No effect On suspicion of underlying central