Olfactory function after mild traumatic brain injury in children-a longitudinal case control study.

The prevalence of posttraumatic olfactory dysfunction in children after mild traumatic brain injury ranges from 3 to 58%, with potential factors influencing this variation, including traumatic brain injury severity and assessment methods. This prospective longitudinal study examines the association between mild traumatic brain injury and olfactory dysfunction in children. Seventy-five pediatric patients with mild traumatic brain injury and an age-matched healthy control group were enrolled. Olfactory function was assessed using the Sniffin' Sticks battery, which focuses on olfactory threshold and odor identification. The study found that children with mild traumatic brain injury had impaired olfactory function compared with healthy controls, particularly in olfactory threshold scores. The prevalence of olfactory dysfunction in the patient group was 33% and persisted for 1 yr. No significant association was found between traumatic brain injury symptoms (e.g. amnesia, loss of consciousness) and olfactory dysfunction. The study highlights the importance of assessing olfactory function in children after mild traumatic brain injury, given its potential impact on daily life. Although most olfactory dysfunction appears transient, long-term follow-up is essential to fully understand the recovery process. The findings add valuable insights to the limited literature on this topic and urge the inclusion of olfactory assessments in the management of pediatric mild traumatic brain injury.

Smelling of the mothers' diet in amniotic fluid by adult noses.

In this study, the transfer of odorants, namely vanilla, and garlic, into the amniotic fluid (AF) during the second trimester was investigated by examination of collected AF samples through healthy adults. Eleven AF samples were collected from pregnant women (aged 32.9 ±â€…4.9 yr, 16-25 wk of gestation) undergoing diagnostic amniocentesis after eating garlic oil or vanilla powder in high-fat yogurt. The control group did not receive food before amniocentesis. Two vanilla, 3 garlic, and 6 control samples were collected through amniocentesis 60-120 min after ingestion. Samples were collected at -80 °C and carefully defrosted over 12 h at the same time point. Sixteen healthy volunteers (8 males, aged 26.5 ±â€…5.0 yr) were asked to judge AF samples with potential garlic or vanilla odors from controls in a 2-alternative forced choice (2AFC) paradigm. Judges were able to identify vanilla in the AF samples with an estimated probability of 50%, resulting in a significant P-value of < 0.001. In contrast, the identification of garlic was unsuccessful with a P-value of 0.86, and only 2 judges were able to identify both vanilla and garlic. According to the results of this study, the vanilla odor probably passes into the amniotic fluid.

A Study on the Impact of the COVID-19 Pandemic on the Aetiology of Paediatric Olfactory Dysfunction.

INTRODUCTION: Although previous studies have examined olfactory dysfunction in children, the novel coronavirus SARS-CoV-2 has certainly had an unprecedented effect on their olfaction, which could not be taken into consideration. The aim of this report was to present data on the epidemiology of olfactory dysfunction during the pandemic and compare this dataset with a pre-pandemic set. We hypothesized an increase in URTI-related olfactory dysfunction. METHODS: Data of paediatric patients consulting a smell and taste clinic between March 2020 and June 2022 were retrospectively analysed. The frequency of major causes of olfactory dysfunction was examined and compared with three subsets of an older dataset. RESULTS: A total of 52 patients were included in the analysis. Most children presented with olfactory dysfunction due to upper respiratory tract infection (URTI) (52%). Congenital olfactory dysfunction was present in 34% of cases. Sinonasal disorders and idiopathic cases accounted for 6 and 4%, respectively, whereas head trauma was the least common cause (2%). This was in contrast with the results of the older set. The frequency of URTI-related olfactory dysfunction increased significantly. The frequency of head-trauma-related or congenital olfactory dysfunction showed marked reductions. There were no significant differences regarding the other aetiologies between our patient cohort and the three subsets. CONCLUSION: The COVID-19 pandemic has resulted in differences regarding the prevalence of aetiologies between our dataset and the subsets of pre-pandemic times. The surge of the frequency of URTI-related olfactory dysfunction may be ascribed to a novel pathomechanism involving sustentacular cells in the olfactory epithelium.

Children and adolescents with primary headaches exhibit altered sensory profiles - a multi-modal investigation.

BACKGROUND: Pediatric headache is an increasing medical problem that has adverse effects on children's quality of life, academic performance, and social functioning. Children with primary headaches exhibit enhanced sensory sensitivity compared to their healthy peers. However, comprehensive investigations including multimodal sensory sensitivity assessment are lacking. This study aimed to compare sensory sensitivity of children with primary headaches with their healthy peers across multiple sensory domains. METHODS: The study included 172 participants aged 6 to 17 years (M = 13.09, SD = 3.02 years; 120 girls). Of these 80 participants were patients with migraine, 23 were patients with tension-type headache, and 69 were healthy controls. The following sensory measures were obtained: Mechanical Detection Threshold (MDT), Mechanical Pain Threshold (MPT), Mechanical Pain Sensitivity (MPS), detection and pain threshold for Transcutaneous Electrical Nerve Stimulation (TENS), olfactory and intranasal trigeminal detection threshold, and odor identification ability. Sensory sensitivity was compared between groups with a series of Kruskal-Wallis tests. Binomial regression models were used to compare the relative utility of sensory sensitivity measures in classifying participants into patients and healthy controls, as well as into patients with migraine and tension-type headache. RESULTS: Patients with migraine had lower MPT measured at the forearm than patients with tension-type headaches and healthy controls. MPS was higher in patients with migraine than in healthy controls. All patients with headaches had lower detection threshold of TENS and higher olfactory sensitivity. Healthy controls showed increased intranasal trigeminal sensitivity. Scores in MPS, TENS, and olfactory and trigeminal thresholds were significantly predicting presence of primary headaches. Additionally, scores in MPT, olfactory and trigeminal threshold were positive predictors of type of headache. CONCLUSIONS: Children with primary headaches exhibit different sensory profiles than healthy controls. The obtained results suggest presence of increased overall, multimodal sensitivity in children with primary headaches, what may negatively impact daily functioning and contribute to further pain chronification. TRIAL REGISTRATION: The study was registered in the German Registry of Clinical Trials (DRKS) DRKS00021062.

Olfactory training effects in children after mild traumatic brain injury.

OBJECTIVE: Mild traumatic brain injury (mTBI) might impair the sense of smell and cognitive functioning. Repeated, systematic exposure to odors, i.e., olfactory training (OT) has been proposed for treatment of olfactory dysfunctions, including post-traumatic smell loss. Additionally, OT has been shown to mitigate cognitive deterioration in older population and enhance selected cognitive functions in adults. We aimed to investigate olfactory and cognitive effects of OT in the pediatric population after mTBI, likely to exhibit cognitive and olfactory deficits. METHODS: Our study comprised 159 children after mTBI and healthy controls aged 6-16 years (M = 9.68 ± 2.78 years, 107 males), who performed 6-months-long OT with a set of 4 either high- or low-concentrated odors. Before and after OT we assessed olfactory functions, fluid intelligence, and executive functions. RESULTS: OT with low-concentrated odors increased olfactory sensitivity in children after mTBI. Regardless of health status, children who underwent OT with low-concentrated odors had higher fluid intelligence scores at post-training measurement, whereas scores of children performing OT with high-concentrated odors did not change. CONCLUSION: Our study suggests that OT with low-concentrated odors might accelerate rehabilitation of olfactory sensitivity in children after mTBI and support cognitive functions in the area of fluid intelligence regardless of head trauma.

Genetics of congenital olfactory dysfunction: a systematic review of the literature.

Olfaction, as one of our 5 senses, plays an important role in our daily lives. It is connected to proper nutrition, social interaction, and protection mechanisms. Disorders affecting this sense consequently also affect the patients' general quality of life. Because the underlying genetics of congenital olfactory disorders (COD) have not been thoroughly investigated yet, this systematic review aimed at providing information on genes that have previously been reported to be mutated in patients suffering from COD. This was achieved by systematically reviewing existing literature on 3 databases, namely PubMed, Ovid Medline, and ISI Web of Science. Genes and the type of disorder, that is, isolated and/or syndromic COD were included in this study, as were the patients' associated abnormal features, which were categorized according to the affected organ(-system). Our research yielded 82 candidate genes/chromosome loci for isolated and/or syndromic COD. Our results revealed that the majority of these are implicated in syndromic COD, a few accounted for syndromic and isolated COD, and the least underly isolated COD. Most commonly, structures of the central nervous system displayed abnormalities. This study is meant to assist clinicians in determining the type of COD and detecting potentially abnormal features in patients with confirmed genetic variations. Future research will hopefully expand this list and thereby further improve our understanding of COD.

Human olfactory dysfunction: causes and consequences.

The sense of smell essentially contributes to social communication, guides nutrition behaviour and elicits avoidance towards environmental hazards. Olfactory smell impairment may hence entail severe consequences for affected individuals. Compared with sensory loss in other modalities, reduced olfactory function is often unnoticed by those affected and diagnosed late. Those patients seeking help frequently suffer from long-term impairments resulting in reduced well-being and quality of life. The current review provides an overview of aetiology, prevalence and specifics of diagnostics in acquired and congenital olfactory loss and focusses on short- and long-term consequences. Compensation strategies are elaborated, and treatment options are mentioned. Individual characteristics associated with the development of serious mental health impairment are discussed in order to help practitioners identifying populations at risk.

Assessment of Olfactory Function in Children and Adolescents: An Overview.

Valid and reliable tools for assessing olfactory function are necessary for the diagnosis of olfactory dysfunction. Olfactory testing can be challenging in a pediatric population due to shorter attention span, linguistic development, and lower olfactory experience in this age group. The aim of this article is to present an overview about olfactory tests that are suitable for a pediatric population. Publications were included when reporting new developed methods of psychophysical olfactory testing in children or adaptation and applications of existing olfactory tests for a pediatric population. Olfactory tests for all 3 major aspects of olfactory function-olfactory threshold, odor discrimination, and odor identification-were included. Olfactory tests were evaluated regarding test validity, test reliability, normative data, and test availability. The current literature shows that several tests are available to assess olfactory function in children. Especially odor identification abilities in a pediatric population are well examined and understood. Tests for olfactory threshold and odor discrimination are less frequently used. In terms of the abovementioned evaluation criteria, only a few tests met all or 3 of these 4 criteria. Based on the current literature the following tests can be recommended for valid and reliable olfactory testing in children: "U-Sniff" odor identification test, the "Sniffin' Sticks" olfactory threshold test, pBOT-6 olfactory threshold and odor identification test, NIH-Toolbox, and Smell Wheel. Age has to be considered when evaluating olfactory function in children.

The Influence of Cognitive Parameters on Olfactory Assessment in Healthy Children and Adolescents.

Olfactory threshold and odor identification tests are frequently used for assessment of olfactory function in children and adolescents. Whether olfactory test results are influenced by cognitive parameters or sex in children and adolescents is largely unknown. The aim of this study was to investigate the influence of cognition, age and sex on "Sniffin' Sticks" olfactory threshold and "U-Sniff" odor identification performance in a pediatric population. A total of 200 participants between age 6 and 17 years were included. Olfactory function (olfactory threshold and odor identification) was assessed using the "Sniffin' Sticks." In addition, age appropriate cognitive testing was applied. The results of this study indicate that odor identification test performance is positively correlated with age (r = 0.31) and verbal abilities of children (r = 0.24). Olfactory threshold results are only marginally influenced by age (r = 0.18) and are not associated with cognitive test performance. Olfactory assessment using olfactory threshold and "U-Sniff" odor identification testing is suitable for children and adolescents when considering age in the interpretation of test results.

Central Nervous System Processing of Floral Odor and Mother's Milk Odor in Infants.

Newborns have a functioning sense of smell at birth, which appears to be highly significant for feeding and bonding. Still, little is known about the cerebral odor processing in this age group. Studies of olfactory function relied mostly on behavioral, autonomic, and facial responses of infants. The aim of the present study was to investigate central odor processing in infants focusing on electroencephalography (EEG)-derived responses to biologically significant odors, namely a food and a non-food odor. A total of 21 term-born, healthy infants participated (11 boys and 10 girls; age range 2-9 months, mean 5.3 ± 2.2 months). Odor stimuli were presented using a computer-controlled olfactometer. Breast milk was used as food odor. Farnesol was presented as a non-food odor. In addition, odorless air was used as a control stimulus. Each stimulus was presented 30 times for 1 s with an interstimulus interval of 20 s. EEG was recorded from 9 electrodes and analyzed in the frequency domain. EEG amplitudes in the delta frequency band differed significantly after presentation of food (breast milk) odor in comparison to the control condition and the non-food odor (farnesol). These changes were observed at the frontal recording positions. The present study indicates that central odor processing differs between a food and a non-food odor in infants. Results are interpreted in terms of focused attention towards a physiologically relevant odor (breast milk), suggesting that olfactory stimuli are of specific significance in this age group.

Odor identification performance in children aged 3-6 years.

BACKGROUND: While valid and reliable olfactory tests have been developed for children aged >5 years, olfactory testing has not systematically been evaluated in younger children. The aim of this study was to evaluate the reliability and validity of the "U-Sniff" odor identification test in children aged 3-6 years. METHODS: We included 160 healthy children (age range 3-6 years) and 14 congenitally anosmic children. Participants were investigated in two identical sessions. The "U-Sniff" test was used to evaluate olfactory function. A picture identification test (PIT) and the Kasel-Concentration-Task (KKA) were administered to identify factors influencing odor identification performance. RESULTS: Age significantly influenced odor identification performance, with older children achieving higher scores. PIT and KKA scores correlated positively with odor identification scores. The "U-Sniff" test demonstrated a high test-retest reliability (r160 = 0.75, p < 0.001). It was possible to distinguish between healthy and anosmic children by means of "U-Sniff" scores starting at age 4 years with high sensitivity (79-93%) and specificity (88-95%). CONCLUSIONS: The "U-Sniff" test is feasible for children starting at age 3 years. In children aged ≥4 years, it is a reliable and valid method to distinguish between normal olfactory function and anosmia. IMPACT: Olfactory testing is reliable and valid starting at an age of 4 years. The study adds a systematic evaluation of olfactory testing in young children. Results of this study are especially interesting for clinicians in the diagnosis of olfactory dysfunction.

Metal-containing Particulate Matter and Associated Reduced Olfactory Identification Ability in Children from an Area of High Atmospheric Exposure in Mexico City.

Air pollution has been linked to poor olfactory function in human adults. Among pollutants, particulate matter (PM) is especially relevant, as it may contain toxic metal ions that can reach the brain via olfactory pathways. Our purpose was to investigate the relation between atmospheric PM and olfactory identification performance in children. Using a validated method, we tested the olfactory identification performance of 120 children, 6-12 years old, from two locations in Mexico City: a focal group (n = 60) from a region with high PM levels and a control group of equal size and similar socioeconomic level from a region with markedly lower PM concentrations. Groups were matched for age and sex. Concentrations of manganese and lead in the hair of participants were determined as biomarkers of exposure. Daily outdoor PM levels were obtained from official records, and indoor PM levels were measured in the children's classrooms. Official records confirmed higher levels of outdoor PM in the focal region during the days of testing. We also found higher classroom PM concentrations at the focal site. Children from the focal site had on average significantly lower olfactory identification scores than controls, and hair analysis showed significantly higher levels of manganese for the focal children but no difference in lead. Children appear to be vulnerable to the effects of air pollution on olfactory identification performance, and metal-containing particles likely play a role in this. Olfactory tests provide a sensitive, noninvasive means to assess central nervous function in populations facing poor air quality.

Influence of chronic diseases on the olfactory function in children.

The association between smell impairment and chronic diseases has been reported in some studies in adults. Such information is not available for chronic diseases in children. The aim of this study was to examine olfactory function of children with chronic diseases such as diabetes mellitus type 1, hypothyroidism, and bronchial asthma in combination with allergic rhinitis in comparison to healthy controls. The data were obtained from n = 205 participants (104 boys, 101 girls) between the age of 6 and 17 years. Seventy-eight of the participants were healthy controls, n = 43 had diabetes mellitus type 1, n = 50 suffer from allergic rhinitis or bronchial asthma, and 34 presented a reduced function of their thyroid in medical history. All participants underwent olfactory testing including olfactory threshold using "Sniffin' Sticks" and odor identification using the "U-Sniff" test. In addition, a depression inventory and cognitive testing using the Ravens Progressive Matrices was performed. No significant difference in olfactory function was observed for any of the chronic diseases in children in comparison to healthy controls. Further analysis showed a trend in significance for a subpopulation of children with bronchial asthma and comorbidities performed worse on the olfactory threshold test compared to patients with bronchial asthma without comorbidities. Pediatric patients suffering from chronic diseases scored higher on the depression inventory compared to healthy controls.Conclusion: In conclusion, this study demonstrates that the influence of chronic diseases (bronchial asthma, diabetes mellitus type 1 and hypothyroidism) on olfactory function in childhood, if any, seems to be insignificant. This is partly in contrast to adult patients. Further research should be conducted in a subgroup of patients with bronchial asthma, allergic rhinitis, and atopic dermatitis or other comorbidities to better understand the association of allergic diathesis and olfactory function and the putative pathogenesis of olfactory dysfunction. What is known: • The association between smell impairment and chronic diseases has been reported in some studies in adults. • Such information is not available for chronic diseases in children. What is new: • The influence of chronic diseases (bronchial asthma, diabetes mellitus type 1, and hypothyroidism) on olfactory function in childhood, if any, seems to be insignificant. • In patients with bronchial asthma and allergic rhinitis, only a subgroup of patients with additional comorbidity (atopic dermatitis) showed a tendency to a reduced sense of smell.

Development of an International Odor Identification Test for Children: The Universal Sniff Test.

OBJECTIVE: To assess olfactory function in children and to create and validate an odor identification test to diagnose olfactory dysfunction in children, which we called the Universal Sniff (U-Sniff) test. STUDY DESIGN: This is a multicenter study involving 19 countries. The U-Sniff test was developed in 3 phases including 1760 children age 5-7 years. Phase 1: identification of potentially recognizable odors; phase 2: selection of odorants for the odor identification test; and phase 3: evaluation of the test and acquisition of normative data. Test-retest reliability was evaluated in a subgroup of children (n = 27), and the test was validated using children with congenital anosmia (n = 14). RESULTS: Twelve odors were familiar to children and, therefore, included in the U-Sniff test. Children scored a mean ± SD of 9.88 ± 1.80 points out of 12. Normative data was obtained and reported for each country. The U-Sniff test demonstrated a high test-retest reliability (r27 = 0.83, P < .001) and enabled discrimination between normosmia and children with congenital anosmia with a sensitivity of 100% and specificity of 86%. CONCLUSIONS: The U-Sniff is a valid and reliable method of testing olfaction in children and can be used internationally.

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.

Influence of Airflow Rate and Stimulus Concentration on Olfactory Event-Related Potentials (OERP) in Humans.

Although the association between odor concentration and olfactory event-related potential (OERP) has been studied, less is known about the influence of airflow on OERP. The aim of this study was to investigate the influence of airflow rate and stimulus concentration on OERP in humans. Electroencephalogram data were collected from young healthy volunteers (n = 17) in separate sessions where 2-phenylethanol (PEA) was delivered in the following conditions: 8 L/min 50% v/v, 8 L/min 30% v/v, 4 L/min 100% v/v, and 4 L/min 60%v/v. Odor concentrations are referred to the %v/v achieved with air dilution and was not measured in the nose. Odor intensity ratings were recorded immediately after stimulus presentation. Data recorded at 5 electrodes (Fz, Cz, Pz, C3, and C4) were pooled and analyzed using both time-domain averaging and single-trial time-frequency domain approaches. Higher airflow rate significantly increased intensity ratings (F = 10.98, P < 0.01), and improved the signal-to-noise-ratio (F = 5.42, P = 0.025). Results from time-frequency analysis showed higher concentration versus lower concentration increased brain oscillations in the slow frequency band (1-3 Hz) at 0-600 ms; while higher airflow rates versus lower airflow rate increased theta-band oscillations (300-600 ms and 5-9 Hz) and decreased delta-band oscillations at 900-1500 ms after stimulus onset. In conclusion, compared to stimulus concentration, airflow rate was associated with improved OERP quality and more pronounced responses. The results suggest that intensity ratings and OERP are strongly related to the steepness of stimulus onset. High airflow rates are suggested for odor delivery in order to record OERP.

Sniffin' Away the Feeding Tube: The Influence of Olfactory Stimulation on Oral Food Intake in Newborns and Premature Infants.

Because of their immaturity, many premature infants are fed via nasogastric tube. One objective of the neonatal care is to feed infants orally early. The olfactory function of premature infants is developed before birth and odorants have a significant impact on nutrition in infants. The aim of the study was to test whether odor stimulation has a positive effect on the transition from gavage to oral feeding in infants. Participants were premature infants with gestational age of more than 27 weeks, with full or partial gavage feeding, stable vital parameters and without invasive ventilation. Before each feeding procedure an odorant was presented in front of the infant's nose. Infants were randomized into 1 of 3 groups and received either rose odor (not food-associated), vanilla odor (food-associated), or placebo (no odor). The primary outcome of the study was defined as the time until complete oral nutrition. About 150 children born at a postnatal age of 9.5 ± 7.8 days were included in this study. The duration until complete oral nutrition was reached after 11.8 ± 7.7 (vanilla), 12.2 ± 7.7 (rose), and 12.9 ± 8.8 (control) days. A nearly linear relation between odor presentation frequency and effect size was detectable. For infants that received the intervention for more than 66.7% of the time the length of gavage feeding (8 ± 5.4) and hospitalization (11 ± 6.5) was significantly lower in the vanilla group when compared with control (15 ± 7.3 and 21 ± 13.7, respectively). Odor stimulation with vanilla has an impact on oral feeding in premature infants, however the odor has to be presented on regular basis.

Effects of "trigeminal training" on trigeminal sensitivity and self-rated nasal patency.

PURPOSE: Patients with the feeling of a congested nose not always suffer from an anatomical obstruction but might just have a low trigeminal sensibility, which prevents them from perceiving the nasal airstream. We examined whether intermittent trigeminal stimulation increases sensitivity of the nasal trigeminal nerve and whether this effect is accompanied by subjective improvement of nasal breathing. METHOD: Thirty-five patients (Mage = 58.4 years; SD = 14.8; Minage = 21 years; Maxage = 79 years; 43% females) and 30 healthy controls (Mage = 36.7 years, SD = 14.5; Minage = 20 years; Maxage = 73 years; 60% females) participated in a study comprised of two sessions separated by "trigeminal training". During each session, trigeminal sensitivity towards CO2, trigeminal lateralization abilities and ratings of nasal patency were assessed. Age and training compliance were controlled. RESULTS: "Trigeminal training" had a positive effect on trigeminal sensitivity in both groups, (p = .027) and this effect depended on the training compliance (p < .001). "Trigeminal training" had no effect on lateralization abilities of the subjects (p > .05). Ratings of nasal patency increased in patients (p = .03), but not in controls. CONCLUSIONS: "Trigeminal training" consisting of intermittent presentation of diverse stimulants leads to an increase of trigeminal sensitivity, but this effect depended on the training compliance. Importantly, in patients, this training is also associated with an increase in self-rated nasal patency.

A Cross-Cultural Adaptation of the Sniffin' Sticks Olfactory Identification Test for US children.

Disorders associated with smell loss are common in adolescents. However, current odor identification tests focus on children from age 6 and older and no cross-cultural test has to date been validated and fully implemented. Here, we aimed to investigate how 3-to-11-year-old US children performed to an adapted and shortened (11 odors instead of 14) version of a European odor identification test-the Sniffin' Kids (Schriever VA, Mori E, Petters W, Boerner C, Smitka M, Hummel T. 2014. The "Sniffin'Kids" test: a 14-item odor identification test for children. Plos One. 9:e101086.). Results confirmed that cued odor identification performance increases with age and revealed little to no differences between girls and boys. Scores below 3 and below 6 may raise hyposmia concerns in US children aged 3-7 years and 8-10 years, respectively. Even though the completion rate of the task reached the 88%, suggesting that children below age 5 were able to finish the test, their performance was relatively poor. In comparing the overall identification performance of US children with that of German children, for whom the test was specifically developed, significant differences emerged, with higher scores obtained by the German sample. Analysis of errors indicated that a lack of semantic knowledge for the olfactory-presented objects may be at the root of poor identification skills in US children and therefore constitutes a problem in the development of an odor identification test for younger children valid across cultures.