Acquired Olfactory Dysfunction in Children and Adolescents: A Systematic Review of the Literature.

Olfactory function can be influenced by many factors and olfactory dysfunction is associated with several diseases. But even considering this, the causes of acquired olfactory dysfunction in children are not well understood. This review was conducted to gain an overview of the etiologies of acquired olfactory dysfunction in a pediatric population. Studies were identified using a predefined literature search, including studies if patients were ≤18 years of age and results of psychophysical olfactory testing were reported. A total of 44 articles met the inclusion criteria for this review and were included in the qualitative analysis. The influence of 6 disease groups on olfactory function in children was observed (otorhinolaryngology, traumatic brain injury, oncology, psychiatric diseases, environmental factors, and other diseases). The current literature is convincing that diseases in the otorhinolaryngology group and traumatic brain injury can lead to acquired olfactory dysfunction, whereas according to the current literature, the role of other influencing factors such as most psychiatric disorders remains uncertain. A number of diseases and circumstances affect olfactory function in children and may cause acquired olfactory dysfunction in this age group. Nevertheless, more research is needed to better understand the causes of acquired olfactory dysfunction in children. Future research should have the goal of early diagnosis and, if possible, early treatment of the condition to prevent a negative impact of olfactory dysfunction on children and adolescents.