Hyposmia in childhood-a comparative evaluation of performance in the 'U-Sniff Test' in children with and without hyperplasia of the lymphoid tissue

ABSTRACT

Background To date, systematic studies on the cause and prevalence of childhood hyposmia are lacking. The causes of this olfactory dysfunction can vary from simple adenoid hyperplasia or a condition following covid-19 infection to the rare Kallmann syndrome. Regardless of the entity, olfactory disorders can not only severely limit children's quality of life but also present a diagnostic challenge. Methods In the period from March to October 2021, 66 children (33 female, 33 male) between 5 and 18 years of age were examined. 41 of these children showed hyperplasia of the lymphatic tissue (adenoid vegetations and/or tonsillar hyperplasia). 25 healthy children without lymphatic hyperplasia were included in the control group. By means of the 'U-Sniff Test', an olfactory test validated for children, the preoperative olfactory ability was assessed. In addition to the known 12 olfactory sticks, we added two additional odors (chewing gum and ethanol). Results 39 % of the children with lymphoid hyperplasia showed a result below 8 points in the 'U-Sniff Test', while the controle group had regular test results. Children with lymphoid tissue hyperplasia were significantly more likely to be diagnosed with hyposmia than are children from the control group (p < 0.01). Odors unpleasant for children, such as fish or coffee, were more reliably detected than fragrant smells. The odor chewing gum was recognized by 91 % of the children in the age group under 6 years of age. The childrens origin or eating habits showed no correlation with their performance in the 'U-sniff Test'. Conclusion Children with lymphoid hyperplasia suffer significantly more often from hyposmia than children without adenoid/tonsillar hyperplasia. There is an evidence gap in the literature regarding this correlation.