Subtle olfactory dysfunction after SARS-CoV-2 virus infection in children

Abstract

Objectives Anosmia/hyposomia have been described as early signs of COVID-19 infection in adults, including young asymptomatic patients who commonly refer olfactory disfunction as their only clinical manifestation. Very few studies involving paediatric age patients have been published until now. This study aims to determine the presence of olfactory dysfunction in children with COVID-19 infection through the use of a self-reported questionnaire and a new olfactory screening tool. Methods Nested case-control study. All paediatric patients screened by reverse transcription polymerase chain reaction (RT-PCR) and Anti-SARS-CoV-2 antibodies for COVID-19 infection, during the study period (March-May 2020), were asked to respond to a questionnaire about symptoms of olfactory disfunction. Patients above six years old also performed an odor identification test based on seven odorants (Kradeo®). This test was designed based on our cultural context and eating habits. Results 126 patients were recruited, including 33 with COVID-19 infection. 15% of the infected children referred anosmia and/or dysgeusia on the questionnaire, all of them were older than eleven years. The results of the odor test (69 patients) revealed subtle disturbances in the infected group (mostly misrecognition of odorants). Median odorant recognition was 3 odors [Interquartile range (IQR) 2-4] in case group and 4 [IQR 3-5] in controls. Male patients showed significantly larger disturbances than girls in both groups (p=0.03). Conclusion Self-referred prevalence of olfactory disfunction in our sample of infected children is lower than that described in adults, especially among the youngest ones, maybe due to immature development of angiotensin-converting enzyme 2 (ACE2) receptors expressed in nasal mucosa. Nevertheless, one month after infection, subtle disturbances (misrecognition of odors) were identified among the infected children. This screening olfactory test provides a hygienic, user-friendly tool, suitable for screening children older than six years of age.

Prevalence of Smell or Taste Dysfunction Among Children With COVID-19 Infection: A Systematic Review and Meta-Analysis

“…A total of 18 studies reported prevalence of smell and/or taste dysfunction, most of them reported more than one type of prevalence among children with COVID-19. Specifically, 11 of the included studies reported the prevalence on smell dysfunction ( 13 , 25 , 27 , 28 , 30 , 34 – 36 , 40 ), 9 of the included studies reported prevalence on taste dysfunction ( 13 , 27 , 28 , 32 , 34 , 37 , 38 , 40 ), 10 of the included studies reported prevalence on smell or taste dysfunction ( 13 , 14 , 25 , 26 , 28 , 29 , 31 , 33 , 36 , 39 ), and 2 of the included studies reported prevalence on smell and taste dysfunction ( 13 , 28 ). Thus, four different types of prevalence were analyzed.…”

Otolaryngology manifestations of COVID-19 in pediatric patients

“…A meta-analysis of the data from Tong et al showed the prevalence of olfactory and gustatory dysfunctions in infected adults of 52.7% and 43.93%, respectively [ 13 ]. However, a lower prevalence has been detected in children as described by Concheiro-Guisan et al, which showed that 15% of infected children, aged 11 and older, reported having anosmia [ 15 ]. In our study, 10.4% and 13.1% of children aged 7-15 years old experienced smell and taste disturbances, respectively.…”

“…The older group in our study reported having taste disturbances significantly more frequently than the group including children between 7 to 10 years of age, with the prevalence of 17.2% and 9.8%, respectively. The lower rates of olfactory and gustatory dysfunctions in pediatrics might be explained by the milder disease course as well as the receptor immaturity [ 15 ]. Studies showed that the sustentacular cells of the olfactory epithelium, which are suggested to have a role in virus entry, are increasing in number as age increases in animal models [ 16 ].…”

“…Only a minority of COVID-19 positive children require admission to the hospital. In a study conducted in the US, the estimated rate of hospitalization ranged from 6% to 20% [ 15 ]. Only 4.4% of the pediatric patients in our study required hospitalization, all of whom were between 3 to 6 years old.…”

Karakteristik Covid-19 pada Anak

“…Gejala Covid-19 yang relatif ringan pada anak-anak akan mudah untuk dilewatkan untuk diagnosis pada tahap awal ketika muncul. Selain itu, berdasarkan penelitian terbaru pada bulan Desember 2020 yang dilakukan oleh Guisan et al (2020), telah ditemukannya gejala lain diantara anak-anak yang terinfeksi, 5/33 (15%) sampel penelitian disebut menderita tanda-tanda klinis anosmia setelah timbulnya infeksi. Apabila berada di daerah epidemi, kemungkinan infeksi SARS-CoV-2 harus dicurigai terutama bagi anak yang menunjukkan gejala riwayat demam atau riwayat kontak dekat dengan kasus terkonfirmasi (Cai et al, 2020).…”