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Notes: Background Allergic rhinitis, asthma and atopic dermatitis are closely associated. Although population-based studies report a high prevalence of rhinitis among asthma patients, less is known of the association between rhinitis and atopic dermatitis and the severity of concomitant rhinitis.Objectives We aimed to determine the prevalence and severity of allergic rhinitis among asthmatics and patients with atopic dermatitis and assessed whether age and comorbidity influence the severity of rhinitis signs and symptoms.Methods Three hundred and twenty-five patients recruited for a multicentre trial to study the effect of encasings of mattresses, pillows and duvets on signs and symptoms of allergic rhinitis and/or asthma and/or atopic dermatitis recorded visual analogue scores (VAS) and daily symptom scores and underwent nasal challenge tests with house dust mite (HDM).Results Based on history and clinical symptoms 92% of the 164 asthmatic patients and 85% of the 86 patients with atopic dermatitis could be diagnosed as having rhinitis. Inclusion of a positive provocation to HDM did not result in a substantial lower prevalence of rhinitis. Subjects reported moderate symptoms, with mean rhinitis VAS scores ranging from 40.0 to 55.0. Presence of atopic dermatitis was associated with lower rhinitis VAS and symptoms scores, whereas in multivariate analysis the presence of asthma was positively associated with nasal responsiveness to HDM.Conclusion The prevalence of nasal symptoms in patients with bronchial asthma or atopic dermatitis and sensitized to house dust mites is high. Although the majority of patients experience mild to moderate symptoms, the presence of nasal disease needs to be examined in all patients with atopic disorders.

Notes: Background Exposure to house dust mite (HDM) allergens can lead to the development of allergic complaints. Mattress covers seem to be an obvious option for lowering allergen exposure in sensitized individuals. Previous studies have shown that Dermatophagoides pteronissinus was the most prevalent HDM species in the Netherlands.Objective In the present study, we investigated the effect of mattress covers on Der p 1 and Der f 1 concentrations in dust samples in three areas in the Netherlands; Groningen, Utrecht and Rotterdam.Methods Dust was obtained from mattresses of 277 patients at the beginning of the study and after 12 months of the placebo-controlled intervention. It was analysed for allergen content by immunoassay. The differential effect of the intervention on Der p 1 vs. Der f 1 was analysed in a subgroup with Der p 1+Der f 1〉1 μg/g dust (N=161). It was tested whether the intervention caused a significant change in the Der f 1/Der p 1 ratio.Results At t=0 we found very similar levels of the group 1 allergens of both species. The relatively high prevalence of D. farinae in our study was geographically restricted: the median Der f 1/Der p 1 ratio was 11.1 in the Rotterdam area compared with 1.32 in the Utrecht area and 0.33 in the Groningen area. Analysis of our data showed that the favourable intervention effect found for the combined allergen data (reduction factor=2.9, P〈0.001) is essentially due to a favourable effect of the intervention on the Der f 1 levels only (reduction factor=3.6, P〈0.001). The effect on the Der p 1 level was remarkably small (reduction factor: 1.2, P=0.48). In the intervention group, the Der f 1/Der p 1 ratio decreased after 12 months by a factor 2.0, whereas in the placebo group it increased (probability of the intervention effect: P〈0.005).Conclusion Mite-impermeable covers are more effective in reducing the level of Der f 1 than that of Der p 1.

Notes: Background Generic and disease-specific quality-of-life (QOL) questionnaires are commonly used in subjects with allergic rhinitis (AR). AR, however, is closely associated with other disorders such as bronchial asthma and atopic dermatitis (AD). These co-morbid associations may have an effect on the inter-relation of generic and disease-specific QOL outcomes and the behaviour of this inter-relation in time.Objective To unravel the inter-relationships between the outcome of a generic instrument (SF-36) and a disease-specific instrument (Rhinitis QOL Questionnaire (RQLQ)).Materials and methods In the framework of a randomized clinical trial with respect to the efficacy of impermeable bedding covers in house dust mite (HDM) allergy, SF-36 and RQLQ were administered to 224 adults with AR and/or allergic asthma and/or AD at baseline and after 12 months of intervention. Regression analysis and canonical correlation were used to estimate overlap.Results Overlap between SF-36 and RQLQ domains in terms of explained variance ranged from 6% to 56%. Canonical correlation yielded low coefficients (0.16–0.27). Moreover, both SF-36 and RQLQ scores did not change significantly during the intervention.Conclusion In patients with HDM allergy characterized by co-morbid associations, SF-36 and RQLQ cover different aspects in QOL. It is advocated to use both simultaneously in performing QOL studies.

Notes: Background:  Environmental control has been put forward as an integral part of the management of house dust mite (HDM) allergy in sensitized patients. To validate this statement allergic disorders involved in HDM allergy – allergic asthma, rhinitis and atopic eczema/dermatitis syndrome (AEDS) – should be taken together and studied in terms of the efficacy of environmental control. Because a generic quality of life questionnaire exceeds the border of disease, this may be used as major outcome parameter.Research objective:  To study the effects of bedding encasings in HDM allergic patients with asthma, rhinitis and AEDS.Material and methods:  A total of 224 adult HDM allergic patients with rhinitis and/or asthma and/or dermatitis were randomly allocated impermeable or nonimpermeable encasings for mattress, pillow and duvet. Short form 36 (SF-36) was filled in at baseline and after 12 months.Results:  Lower physical (P = 0.01) and emotional (P 〈 0.001) sumscores were seen in females. Also, the presence of asthma resulted in lower physical sumscore (P = 0.01). However, no effect was seen of encasings on either sumscore.Conclusion:  Bedding encasings do not improve quality of life in a mixed population of subjects with combinations with rhinitis, asthma and atopic dermatitis and sensitized to HDMs.

Notes: Background: Allergic rhinitis, asthma or the atopic eczema/dermatitis syndrome (AEDS) may independently impair quality of life in patients. However, although many allergic patients may suffer from more than one disorder, the effect of concomitant disease — in particular, the impact of AEDS — is largely unknown. As part of a large multicenter clinical trial on the efficacy of mattress casings in house-dust mite (HDM) allergy, generic quality of life in a mixed population of 224 subjects with rhinitis (n = 198) and/or asthma (n = 111) and/or AEDS (n = 64) was studied. The study aimed to estimate quality of life impairment in these atopic patients and to address the questionissue of whether one atopic disorder goes beyond other existing allergic diseases, thereby causing further impairment to quality of life.Methods: Generic quality of life was assessed by SF-36. Quality of life in the atopic group was compared with a Dutch norm population. Multiple linear regression was used to determine the effects of disease (i.e. the presence of allergic rhinitis, asthma or AEDS) or disease severity, as assessed by visual analog scores (VAS) for asthma, rhinitis, VAS sleeplessness and VAS itching being considered as major symptoms in AEDS on SF-36 domains.Results: Compared to the norm group, atopic patients were impaired in: physical functioning; role physical functioning; general health; vitality; and social functioning. The diagnosis of asthma was negatively associated with the SF-36 subscales for physical functioning (P = 0.02), and general health (P 〈 0.01). In line with these findings, asthma severity (VAS asthma) was negatively associated with physical functioning (P 〈 0.01), role physical functioning (P 〈 0.01), general health (P 〈 0.0.1), social functioning (P = 0.01), emotional functioning (P = 0.01), and vitality (P = 0.01). VAS sleeplessness had significant negative effect on role physical functioning (P 〈 0.01), bodily pain (P 〈 0.01), General health (P = 0.01), mental health (P 〈 0.01), social functioning (P 〈 0.01), and vitality (P 〈 0.01). In contrast, neither the diagnosis of allergic rhinitis or AEDS, nor VAS itching as an outcome parameter of AEDS, exerted additional effects on the SF-36 domains.Conclusions: Patients with atopic disease based on HDM allergy may have impaired quality of life. The majority of these patients have allergic rhinitis. The (co)existence of asthma, expressed in terms of diagnostic criteria or symptom severity, or the presence of sleep disorders as a consequence of AEDS, may further impair quality of life.