Allergic rhinitis causes loss of smell in children: The OLFAPEDRIAL study

V Brazilian Consensus on Rhinitis - 2024

Since we published the "IV Brazilian Consensus on Rhinitis", in2017, several advances have been achieved and have enabled a further understanding of the different aspects of "Rhinitis". This new guideline, developed jointly by ASBAI, SBP and SBORL, represents a relevant milestone in the updated and integrated management of the different forms of the disease, and it aims to unify evidence-based approaches to improve the diagnosis and treatment of this common and often underestimated condition. The document covers a wide range of topics, including clear definitions of the different phenotypes and endotypes of rhinitis, risk factors, updated diagnostic criteria, and recommended methods for clinical and laboratory investigation. We stress the importance of detailed clinical history and objective assessment, as well as tools for control and assessing severity tools an accurate diagnostic approach to the disease. Regarding treatment, it emphasizes the treatment customization, considering the severity of symptoms, the presence of comorbidities and the impact on the patient's quality of life. We discuss different drug treatment, in addition to non-pharmacological measures, such as environmental control and specific immunotherapy; and the possible role of immunobiological agents. Furthermore, the consensus addresses issues related to patient education, prevention and management of special situations, such as rhinitis in children, in pregnant women and in the elderly. In short, the "V Brazilian Consensus on Rhinitis" represents a comprehensive and updated guide for healthcare professionals involved in the diagnosis and management of rhinitis, aiming to improve patients' quality of life through an integrated and evidence-based approach.

Olfactory Dysfunction in Allergic Rhinitis

Olfactory dysfunction (OD) can have serious consequences as it hinders individuals from detecting important warning signals like smoke, spoiled food, and gas leaks. This can significantly impact their nutritional status, eating satisfaction, and overall quality of life. Allergic rhinitis (AR) is a common disease that greatly affects the quality of life and can lead to a decrease, distortion, or complete loss of olfactory ability. There are various tools available for diagnosing OD, ranging from simple screening tests to more detailed and complex methods such as electrophysiological and imaging procedures not available in everyday practice but reserved for experimental studies. The underlying mechanisms by which AR impacts olfactory ability are still not fully understood and are likely to be multifactorial. Current therapeutic options for OD resulting from AR are limited and only provide partial or temporary relief from olfactory impairment. However, there are promising treatments investigated such as biologics, olfactory training, neural stem cell transplantation, and various novel target therapies that might help improve OD in AR in the future. This review aims to evaluate the epidemiology, mechanisms, and detection of OD in AR, as well as provide an overview of the management strategies for OD secondary to AR.

Olfactory dysfunction in Japanese children with moderate-to-severe allergic rhinitis

OBJECTIVE

Detailed quantitative studies on olfaction remain inadequate in patients with paediatric allergic rhinitis (AR). This study examined olfactory dysfunction in children with AR.

METHODS

From July 2016 to November 2018, children aged 6-9 years were recruited and grouped as AR (n = 30) or without AR (control group, n = 10). Odour identification was evaluated by the Universal Sniff (U-Sniff) test and the Open Essence (OE). The results were compared between the AR and control groups. Intranasal mucosa findings, nasal smear eosinophil counts, blood eosinophil counts, total immunoglobulin E (IgE) levels, Japanese cedar-specific IgE and Dermatophagoides pteronyssinus-specific IgE were evaluated in all participants. Additionally, the presence of sinusitis and adenoid hypertrophy in patients with AR was also evaluated by sinus X-ray examinations.

RESULTS

The median U-Sniff test scores were not significantly different between the AR and control groups (9.0 vs. 10.0, respectively; p = 0.107). The OE score was significantly lower in the AR group than in the control group (4.0 vs. 8.0; p = 0.007, respectively), especially in the moderate-to-severe AR group versus the control group (4.0 vs. 8.0; p = 0.004). Furthermore, in the OE, the correct answer rates for 'wood', 'cooking gas' and 'sweaty socks' were significantly lower in the AR group than in the control group.

CONCLUSIONS

Paediatric AR patients can reduce olfactory identification ability, and the degree may be associated with the severity of AR in nasal mucosal findings. Furthermore, olfactory dysfunction may slow down the response to 'emergency situations', such as gas leak.

Neurons, Nose, and Neurodegenerative Diseases: Olfactory Function and Cognitive Impairment

Olfactory capacity declines with aging, but increasing evidence shows that smell dysfunction is one of the early signs of prodromal neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The study of olfactory ability and its role in neurodegenerative diseases arouses much interest in the scientific community. In neurology, olfactory impairment is a potential early marker for the onset of neurodegenerative diseases, but the underlying mechanism is poorly understood. The loss of smell is considered a clinical sign of early-stage disease and a marker of the disease's progression and cognitive impairment. Highlighting the importance of biological bases of smell and molecular pathways could be fundamental to improve neuroprotective and therapeutic strategies. We focused on the review articles and meta-analyses on olfactory and cognitive impairment. We depicted the neurobiology of olfaction and the most common olfactory tests in neurodegenerative diseases. In addition, we underlined the close relationship between the olfactory and cognitive deficit due to nasal neuroepithelium, which is a direct extension of the CNS in communication with the external environment. Neurons, Nose, and Neurodegenerative diseases highlights the role of olfactory dysfunction as a clinical marker for early stages of neurodegenerative diseases when it is associated with molecular, clinical, and neuropathological correlations.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Radiofrequency ablation turbinoplasty improves the sense of smell in pediatric patients: A prospective study

INTRODUCTION

The olfactory sense is of paramount importance for the adequate development of a child. Olfactory loss in children might have different origins. One of the most common is conductive, when nasal obstruction prevents odorants from reaching the olfactory epithelium. Rhinitis and turbinate enlargement have been proven to diminish the sense of smell in pediatric patients. A common treatment for resistant rhinitis in these patients is turbinate radiofrequency ablation (TRA). However, despite an increasing research effort in this field, there are no studies instrumentally assessing olfaction in children undergoing turbinate surgery to date. This study was designed with the aim of assessing changes in olfaction through validated instrumental tools in pediatric patients undergoing TRA for the first time.

METHODS

A prospective uncontrolled intervention clinical trial design was conducted. Two cohorts of children ranging 4-15 years old were consecutively selected from a third level referral Hospital and subjected to the universal sniff test (U-Sniff), alcohol sniff test (AST), and sniffin sticks threshold test (SST) before and 1, 3 and 6 months after surgery. Cohort A consisted of children solely undergoing TRA. Cohort B consisted of children on whom adenoidectomy and TRA had been performed. Additionally, a cohort of Spanish healthy controls, paired by sex and age, were asked to perform the U-Sniff.

RESULTS

A total of 81 participants with a mean age of 10.31 ± 2.56 years were included. Fifty-three patients underwent TRA exclusively and 28 were subjected to associated adenoidectomy. Despite a tendency toward improvement in the U-sniff scores, there were no statistically significant differences after surgery. However, statistically significant differences were obtained for threshold tasks measured with SST and AST, revealing differences at 1, 3 and 6 months after surgery compared to preoperative scores.

CONCLUSIONS

In summary, this research demonstrated adequate levels in the sense of smell regarding identification tasks, but decreased olfactory threshold scores in pediatric patients suffering from TE. TRA, alone or with adenoidectomy, improved smell threshold scores, but had no significant effect on identification tasks.

Atopic Dermatitis-Beyond the Skin

Atopic dermatitis is a chronic inflammatory disease that can arise during the first months of life or at maturity and have a significant negative impact on the quality of life. The main pathogenic mechanism is the breakdown of cutaneous barrier integrity, which is associated with systemic inflammatory immunologic disorders. Atopic dermatitis involves numerous immunologic, allergic, respiratory, and ophthalmologic comorbidities that develop through similar intricate pathogenic phenomena. The atopic march represents the evolution in time of various allergic diseases, of which food allergies often cause the first manifestations of atopy, even from a very young age. Chronic inflammation translated through specific markers, next to increased immunoglobulin E (IgE) serum levels and heterogenous clinical manifestations, argue for the inclusion of atopic dermatitis in the systemic disease category.

Rhinitis Phenotypes

Rhinitis is an umbrella term of a group of upper airway diseases with nasal symptoms and signs with different etiologies and various clinical features or traits. It can be classified into different "phenotypes," based on these observable traits. A proper differential diagnosis is necessary to adequately manage the disease. The objective of this review is to clarify the concept of rhinitis phenotypes while analyzing the clinical features and/or traits of each in order to determine a proper differential diagnosis and appropriate treatment.

Evaluation of Olfactory Function in Children With Vernal Keratoconjunctivitis

BACKGROUND

Vernal keratoconjunctivitis (VKC) is a chronic, severe allergic disease of the conjunctiva, which mostly affects young males in early to mid-childhood. There is a high incidence of asthma, allergic rhinitis (AR) and eczema among patients with VKC. It is unknown if VKC patients have abnormal olfactory dysfunction, and if so, whether this is related to AR.

OBJECTIVE

Our aim was to evaluate olfactory function in children with VKC, with and without comorbid AR, in comparison to healthy children without VKC.

MATERIALS AND METHODS

Thirty-nine VKC patients and 32 healthy children were included in the study. After eye and ear, nose and throat (ENT) examination, acoustic rhinometry and modified Connecticut Chemosensory Clinical Research Center (CCCRC) tests were performed and the test results were compared between VKC and control groups and between VKC children with or without AR. A p value <0.05 was regarded as statistically significant.

RESULTS

The VKC group included 25 males (64.1%) with a mean age of 11.13 ± 3.22 years, while the control group included 26 males (81.3%) with a mean age of 12.50 ± 2.13 years (p > 0.05 for both age and gender). Fourteen VKC patients (35.9%) had either positive prick test or elevated serum specific IgE levels against house dust mites and pollens. Mean odor thresholds did not differ between the two groups (p = 0.084), while mean odor identification and CCCRC score were statistically significantly lower in VKC group (6.00 ± 1.02 and 6.81 ± 0.75, respectively) compared to control group (7.06 ± 0.77 and 7.5 ± 0.41, respectively) (p < 0.05, both). Thirteen VKC patients had co-associated AR (33.3%). In VKC patients with AR, mean odor threshold and identification scores were even lower (5.31 ± 0.95 and 6.23 ± 0.78, respectively) (p < 0.05, both).

CONCLUSION

Olfactory function was found to be mildly impaired in children with VKC, especially when co-associated with AR. Therefore, loss of smell should be asked as an extraocular symptom.

Olfactory Dysfunction in a Mexican Population Outside of COVID-19 Pandemic: Prevalence and Associated Factors (the OLFAMEX Study)

PURPOSE OF REVIEW

To study the prevalence of olfactory loss and its associated factors in a Mexican population a cross-sectional analytical study based on a population interviewed about health, epidemiologic aspects, and sense of smell (tested with four scents: rose, banana, perfume, and gas) was conducted to evaluate olfactory detection, memory, and identification. Levels of sense of smell perception were determined when the participants detected, recognized, or identified all (normosmia), 1-3 (hyposmia), or none (anosmia) of the odorants. Associated factors of olfactory dysfunction were identified by multivariate analysis (odds ratio, 95%CI).

RECENT FINDINGS

Olfactory dysfunction is a prevalent disorder affecting up to 20% of the general population. In addition to viral infection, including COVID-19, a number of other causes and factors may also be involved. 1,956 surveys were conducted and 1,921 were analyzed. Most of the participants (62.1%) were women. The general prevalence of olfactory dysfunction, regarding detection, was 7.2% (7.1% hyposmia, 0.1% anosmia). Age-related olfactory deterioration was observed in both sexes from the 5th decade of life (OR 2.74, p = 0.0050). Women showed better olfactory identification (OR 0.73, p = 0.0010). Obesity (OR 1.97, p = 0.0070), low educational level, bad/very bad self-perceived olfactory function (OR 2.74, p = 0.0050), olfactory loss for less than one week (OR 1.35, p = 0.0030), exposure to toxics/irritants (OR 1.31, p = 0.0030), active smoking (OR 1.58, p < 0.0010), and type 2 diabetes mellitus (OR 2.68, 95%CI 1.74-4.10, p < 0.0001) were identified as factors associated with olfactory dysfunction. These results in a Mexican population suggest better olfactory identification (verbalization) in females. Age was a determining factor in the olfactory deterioration process and obesity and diabetes mellitus were also associated with olfactory disorders. Finally, these findings reinforce the differential diagnosis with other potential causes of sense of smell loss, during the COVID-19 outbreak.

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.

Multimorbidities of Pediatric Allergic Rhinitis

PURPOSE OF REVIEW

Most children and adolescents with allergic rhinitis (AR) present extra-nasal multimorbid conditions, including conjunctivitis, asthma, atopic dermatitis, rhinosinusitis, or seromucous otitis. Additionally, they may present nasal obstructive disorders, such as septal deformity, turbinate enlargement, and adenoidal hyperplasia, which worsen nasal symptoms, especially nasal obstruction. This is a narrative review on the current state of the concomitant presence of AR and one or more multimorbidities.

RECENT FINDINGS

The presence of AR and one or more accompanying multimorbidities is associated to a higher severity and duration of the disease, a negative impact on quality of life, with worse control and lack of improvement with medical treatment. Therefore, AR needs to be managed with a multidisciplinary collaborative approach. Pediatric AR needs to be considered in the context of a systemic disease, which requires a coordinated therapeutic strategy.

Evaluation of olfactory function in children with seasonal allergic rhinitis and its correlation with acoustic rhinometry

OBJECTIVES

Seasonal allergic rhinitis (SAR) is common in children and hyposmia is a major symptom affecting the quality of life. The aim of the present study is to assess olfactory dysfunction in pediatric patients with SAR and correlate the results with acoustic rhinometry measurements.

METHODS

Forty children, diagnosed as moderate and severe SAR based on clinical findings, ARIA (Allergic rhinitis and it's impact on asthma) classification and prick test results were enrolled in the study. Endoscopic nasal examination, acoustic rhinometry, total nasal symptom score (TNSS) and Connecticut Chemosensory Clinical Research Center (CCCRC) tests were performed 'in season' (May-August) and 'out season' (November-February). Three patients who did not show up in 'out season' examinations were excluded from the study.

RESULTS

The ages of the children ranged between 8 and 18 years with a hyposmia increased and odor identification decreased (p < 0.005, p = 0.003, respectively), whereas no differences were found between odor thresholds and the discrimination values (p > 0.05). Mean CCCRC value was obstruction score (r =-0.340, p = 0.04), subjective hyposmia (r = -0.44, p = 0.007) and TNSS (r = -0.494, p = 0.02). Although some of the acustic rhinometry parameters were lower during allergy season, there were no correlations between acoustic rhinometry parameters and CCCRS values.

CONCLUSION

Nearly half of the children with AR reported a mild to moderate hyposmia during pollen season and there was a decrease in odor identification, which can be easily shown using a CCCRC test.

Olfactory Dysfunction in Neurodegenerative Diseases

PURPOSE OF REVIEW

The sense of smell is today one of the focuses of interest in aging and neurodegenerative disease research. In several neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease, the olfactory dysfunction is one of the initial symptoms appearing years before motor symptoms and cognitive decline, being considered a clinical marker of these diseases' early stages and a marker of disease progression and cognitive decline. Overall and under the umbrella of precision medicine, attention to olfactory function may help to improve chances of success for neuroprotective and disease-modifying therapeutic strategies.

RECENT FINDINGS

The use of olfaction, as clinical marker for neurodegenerative diseases is helpful in the characterization of prodromal stages of these diseases, early diagnostic strategies, differential diagnosis, and potentially prediction of treatment success. Understanding the mechanisms underlying olfactory dysfunction is central to determine its association with neurodegenerative disorders. Several anatomical systems and environmental factors may underlie or contribute to olfactory loss associated with neurological diseases, although the direct biological link to each disorder remains unclear and, thus, requires further investigation. In this review, we describe the neurobiology of olfaction, and the most common olfactory function measurements in neurodegenerative diseases. We also highlight the evidence for the presence of olfactory dysfunction in several neurodegenerative diseases, its value as a clinical marker for early stages of the diseases when combined with other clinical, biological, and neuroimage markers, and its role as a useful symptom for the differential diagnosis and follow-up of disease. The neuropathological correlations and the changes in neurotransmitter systems related with olfactory dysfunction in the neurodegenerative diseases are also described.

Olfactory assessment in the Chinese pediatric population

Young children with olfactory disturbance are sometimes encountered in ENT clinics. We investigated the clinical applicability of olfactory testing to the pediatric population in China.One hundred and ninety-three healthy children aged 6 to 17 years were enrolled. All participants were asked for demographic information (age, sex, body mass index [BMI], and rating of olfactory function) in a structured questionnaire and underwent olfactory testing including T&T Olfactometer (T&T), odor discrimination (OD), and odor identification (OI) tests of Sniffin' Sticks.Age had a significant influence on the outcome of olfactory testing, sex, BMI, or self-rating had no influence. Children had better performance on T&T than OI and OD tests of Sniffin' Sticks.T&T and Sniffin' Sticks can be completed by Chinese children. Performance on olfactory tests increased with increasing age. T&T may be more suitable to assess olfactory function in the Chinese pediatric population.