Prevalence of IgE sensitization in Danish children with suspected asthma

Chronological changes in rhinitis symptoms present in school-aged children with allergic sensitization

Introduction

It is difficult to accurately predict the natural course of allergic rhinitis (AR), because it is affected by a wide variety of environmental influences, as well as genetic predisposition. Considering the high prevalence of allergic rhinitis in children and adolescents, caregivers should be given appropriate information regarding the disease course. This study aimed to understand the prognosis of allergic rhinitis by examining the relationship between allergic sensitization and rhinitis symptoms during this developmental period.

Methods

This cross-sectional study included 1069 children aged 9–16 years from the Korean International Study of Asthma and Allergies in Childhood Survey database who had completed health questionnaires, and for whom skin prick test results were available. Data were collected during May 2016. The distribution of sensitization and allergic symptoms was compared by age groups (elementary, middle, and high school). Data were analyzed using linear-by-linear analysis.

Results

Sensitization to at least one tested allergen differed by age (59.2%, 58.3%, 68.2%, in elementary, middle, and high school students, respectively; p = 0.025), and seasonal allergen sensitization (35.0%, 37.1%, 53.9%, respectively) increased with age (p < 0.001). Conversely, the proportion of rhinitis symptoms among sensitized children decreased as age increased (58.80%, 52.90%, 49.70%, respectively; p = 0.047). However, the rate of non-allergic rhinitis was age-independent.

Conclusion

With increasing age during childhood and adolescence, symptomatic allergic rhinitis decreases; thus, subclinical allergic rhinitis increases. This suggests that the symptoms of later-sensitized children are less clearly manifested, or that the symptoms reduce as previously sensitized children mature. This should be clarified further in a longitudinal study.

Validity of asthma diagnoses and patterns of anti-asthmatic drug use in a cohort of 2053 Danish children

BACKGROUND AND AIMS

When investigating and treating asthma in children, diagnosing must be precise and valid. There is a need for studies researching asthma in children showing how to use registry-based, epidemiological data. We examined the feasibility and validity of using anti-asthmatic drug prescription data to identify children with asthma and assessed medication patterns in children with and without confirmed asthma.

METHODS

We used population-based Danish prescription data and hospital discharge registries to identify all children aged 0 to 14 years who had redeemed at least one prescription for an inhaled anti-asthmatic drug. Individual asthma cases were validated by hospital discharge information and by their treating general practitioners according to international asthma guidelines.

RESULTS

In total, 2053 children, out of a population of 20181, had redeemed at least one prescription of any inhaled anti-asthmatic drug. The positive predictive value (PPV) of having two different asthma medications prescribed in 1 year was 80.2% for presence of true asthma, with a sensitivity of 59%. Corresponding estimates of PPV/sensitivity of at least one prescription for an inhaled corticosteroid (ICS) were 79% and 58%, respectively, while the true asthma PPV with at least one LABA prescription increased to 97%. Among children with confirmed asthma, one-third had not used Beta2-agonist therapy as part of their treatment. Conversely, among children without confirmed asthma, 40% were prescribed a minimum of two prescriptions for any kind of inhaled anti-asthmatic drug, and 12% and 9% used an ICS or Leukotriene receptor antagonist, respectively.

CONCLUSIONS

Anti-asthmatic drug prescription data could be used to identify children with true asthma, with reasonable accuracy. The observed pattern of anti-asthmatic medication usage among children with and without confirmed asthma suggests that there is room for therapeutic improvement.

Associations Between Asthma and Sensitization to Pet or Pollen Allergens in Young Swedish Twins - The STOPPA Study

BACKGROUND

An association between childhood asthma and IgE sensitization has been established, but our understanding of the genetic and environmental contribution to it is incomplete. Our aim was to estimate the associations and dose-response relationship between asthma and sensitization to airborne allergens in Swedish 9- to 14-year-old twins. Additionally, we aimed to explore the importance of familial confounding from shared genes and environment using co-twin controls.

METHODS

In the STOPPA cohort, 752 same-sex twin children were screened with Phadiatop® (Thermo Fisher Scientific; Pharmacia, Uppsala, Sweden); if positive further analysis of IgE antibodies to airborne allergens of pets (cat, horse, dog), pollens (birch, timothy, mugwort), mites, and mold were performed. The associations between asthma and airborne allergens were assessed with generalized estimating equations. The co-twin control analysis was performed by conditional logistic regression.

RESULTS

Children with positive Phadiatop® had more than doubled odds of asthma (OR 2.53, 95% CI [1.74, 3.70]). Sensitization to pet allergens was associated with increased odds of asthma; for example, cat OR 4.15 (95% CI [2.67, 6.45]), with similar estimates for pollens; for example, birch OR 3.22 (95% CI [2.12, 4.91]). Associations persisted with sensitization as a categorical variable and for trend, indicating a dose-response relationship. Results remained in the co-twin analyses; for example, cat OR 4.75 (95% CI [1.62, 14.0]) and birch OR 5.00 (95% CI [1.45, 17.3]).

CONCLUSION

The association between childhood asthma and sensitization to airborne allergens remains in co-twin analyses, indicating they are not due to confounding from shared environmental or genetic factors.

The Danish National Database for Asthma: establishing clinical quality indicators

Asthma is one of the most common chronic diseases worldwide affecting more than 300 million people. Symptoms are often non-specific and include coughing, wheezing, chest tightness, and shortness of breath. Asthma may be highly variable within the same individual over time. Although asthma results in death only in extreme cases, the disease is associated with significant morbidity, reduced quality of life, increased absenteeism, and large costs for society. Asthma can be diagnosed based on report of characteristic symptoms and/or the use of several different diagnostic tests. However, there is currently no gold standard for making a diagnosis, and some degree of misclassification and inter-observer variation can be expected. This may lead to local and regional differences in the treatment, monitoring, and follow-up of the patients. The Danish National Database for Asthma (DNDA) is slated to be established with the overall aim of collecting data on all patients treated for asthma in Denmark and systematically monitoring the treatment quality and disease management in both primary and secondary care facilities across the country. The DNDA links information from population-based disease registers in Denmark, including the National Patient Register, the National Prescription Registry, and the National Health Insurance Services register, and potentially includes all asthma patients in Denmark. The following quality indicators have been selected to monitor trends: first, conduction of annual asthma control visits, appropriate pharmacological treatment, measurement of lung function, and asthma challenge testing; second, tools used for diagnosis in new cases; and third, annual assessment of smoking status, height, and weight measurements, and the proportion of patients with acute hospital treatment. The DNDA will be launched in 2016 and will initially include patients treated in secondary care facilities in Denmark. In the nearby future, the database aims to include asthma diagnosis codes and clinical data registered by general practitioners and specialised practitioners as well.

The Danish National Database for Asthma

AIM OF THE DATABASE

Asthma is the most prevalent chronic disease in children, adolescents, and young adults. In Denmark (with a population of 5.6 million citizens), >400,000 persons are prescribed antiasthmatic medication annually. However, undiagnosed cases, dubious diagnoses, and poor asthma management are probably common. The Danish National Database for Asthma (DNDA) was established in 2015. The aim of the DNDA was to collect the data on all patients treated for asthma in Denmark and to monitor asthma occurrence, the quality of diagnosis, and management.

STUDY POPULATION

Persons above the age of 6 years, with a specific focus on 6-44 years, are included. The DNDA links three existing nationwide registries of administrative records in the Danish health care system: the National Patient Register, the National Health Insurance Services Register, and the National Prescription Registry. For each year, the inclusion criteria are a second purchase of asthma prescription medicine within a 2-year period (National Prescription Registry) or a diagnosis of asthma (National Patient Register). Patients with chronic obstructive pulmonary disease are excluded, but smokers are not excluded.

DESCRIPTIVE DATA

A total of 366,471 prevalent patients with asthma have been identified (year 2014 - as a preliminary test search). This number is in agreement with the estimates of ~400,000 inhabitants that are available for patients with possible asthma in Denmark. Data encompass the following quality indicators: annual asthma control visits and pharmacological therapy.

MAIN VARIABLES

The variables included are spirometry, as well as tools for diagnosis (including allergy testing), smoking status, height, weight, and acute hospital admissions and unscheduled visits.

CONCLUSION

DNDA is available from January 1, 2016.

Respiratory allergies in childhood: Recent advances and future challenges

The burden of allergic airway diseases still represents a major health problem in childhood. Despite many different options are currently available for the diagnostic work-up and management, the overall disease control in terms of impact on quality of life, morbidity and mortality, is not yet satisfactory. The extreme variability of individual risk factors and severity determinants may account for it. On the other side, the knowledge of the multifaceted allergy background could pave the way to primary prevention, early intervention and disease course modification. In fact, most of current research is focusing on the identification of biological and clinical predictive markers of allergy and asthma onset. This review aims at summarizing the latest achievements concerning the complex inter-relation between genetic predisposition and environmental factors, and their impact on prevention strategies and early identification of at risk subjects. An update on the diagnostic and monitoring tools as well as an insight into the newest treatments options is also provided.

Patterns of Sensitization to Inhalant Allergens in Japanese Lower-Grade Schoolchildren and Related Factors

OBJECTIVE

This study clarified sensitization patterns to house dust mite (HDM) and Japanese cedar pollen (JCP) in Japanese lower-grade schoolchildren. We also explored factors associated with allergic sensitization.

METHODS

This cross-sectional study used a database from the Study on Respiratory Disease and Automobile Exhaust (SORA), a Japanese health study project. The subjects comprised 8,815 pupils aged 6-9 years. We obtained the distribution of HDM- and JCP-specific IgE, respectively, as a marker of sensitization. To determine factors associated with sensitization, we used logistic regression and calculated adjusted odds ratios (AORs) for the relative prevalence of sensitization. The cut-off point for specific IgE levels was 0.35 kU/l.

RESULTS

Sensitization to HDM and JCP was detected in 51 and 39% of subjects, respectively, occurring more often in boys and at older ages. In addition, AORs of sensitization to HDM/JCP were higher in subjects with a history of bronchitis, parental asthma, parental atopic eczema and parental pollinosis. In contrast, AORs for sensitization were lower in those subjected to maternal passive smoking as well as among boys with pets. AORs of sensitization to JCP alone were lower in those with a history of otitis media, those who had been bottle milk fed, and those who were not the firstborn and who lived near a busy road.

CONCLUSION

Sensitization to HDM and JCP was detected in 51 and 39% of lower-grade schoolchildren, respectively.

Latex hypersensitivity among allergic Egyptian children: relation to parental/self reports

BACKGROUND

Latex allergy is one of the major health concerns and allergic reactions to latex may be serious and fatal.

PURPOSE

In this study, we sought to determine the frequency of latex hypersensitivity in a group of allergic Egyptian infants and children and its relation to the history provided by the patients or caregivers.

METHODS

We consecutively enrolled 400 patients with physician diagnosed allergic diseases. The study measurements included clinical evaluation for the site and duration of allergy, history suggestive of latex allergy, family history of allergy, and skin prick testing (SPT) using a commercial latex extract.

RESULTS

The study revealed that 16/400 (4%) patients had positive SPT; 11 of them only had positive history of sensitivity to latex. Positive latex SPT was reported in 3.4% (11/326) of patients with bronchial asthma, 5.9% (7/118) of patients with skin allergy, and 4.5% (2/44) of patients with allergic rhinitis. SPT was positive in 7.4% (4/54) of patients with concomitant respiratory and skin allergy. Latex SPT was more specific than sensitive (97.69% and 77.77%, resp.) with a negative predictive value of 99.47%.

CONCLUSION

Although underrecognized, latex is an important allergen in the pediatric age group with a sensitization frequency of 4% among allergic children. It was observed to be especially associated with multiple allergic diseases coexisting in the same patient. Pediatric allergologists should educate their patients on latex allergy and encourage the use of latex-free products.