Search PubMed⌕ Search

Biomedical subjects

H Mosbech

Publications and source records attributed to H Mosbech.

At least 19 recordsLinked to original sources

Side-effects of allergen-specific immunotherapy: a prospective multi-centre study.

BACKGROUND AND OBJECTIVE: The safety of allergen-specific immunotherapy (SIT) is a parameter of great interest in the overall assessment of the treatment. A clinical database was developed in order to obtain early warnings of changes in the frequency and severity of side-effects and sufficient data for the evaluation of possible risk factors. METHODS: During a 3-year period, four allergy centres in Copenhagen, Denmark, included data from all patients initiating SIT to a common database. Information on initial allergic symptoms, allergens used for treatment, treatment regimens and systemic side-effects (SSEs) during the build-up phase was collected. RESULTS: A total of 1,038 patients received treatment with 1,709 allergens (timothy, birch, mugwort, house dust mite (HDM), cat, and wasp and bee venom), 23,047 injections in total. Most SIT patients completed the updosing phase without side-effects, but there was a significant difference between allergens: wasp (89%), birch (82%), HDM (81%), cat (74%) and grass (70%) (P=0.004). A total of 582 SSEs were registered in 341 patients. Most side-effects were mild grade 2 reactions (78%). A difference in severity between allergens was observed (P=0.02), with grass giving most problems. The type of allergen but not patient- or centre-related parameters seemed predictive of side-effects. CONCLUSIONS: Allergen extracts differ in their tendency to produce side-effects. Multi-centre studies like the present one allow more patients to be evaluated, and thereby provide a more efficient surveillance of side-effects. Online Internet-based registration to a central national database of every allergen injection would be an even more powerful tool for evaluation of risk factors and surveillance of side-effects.

Adolescent↗

Exposure of eyes to perfume: a double-blind, placebo-controlled experiment.

Environmental perfume exposure can elicit bothersome respiratory symptoms. Symptoms are induced at exposure levels which most people find tolerable, and the mechanisms are unclear. The aim of the study was to investigate patients with eye and respiratory symptoms related to environmental perfume, by exposing the eyes to perfume in a double-blind, placebo-controlled study.Twenty-one eczema patients with respiratory symptoms elicited by perfume were compared with 21 healthy volunteers in a sex- and age-matched case-control study. The participants completed a symptom questionnaire, and underwent a double-blind, placebo-controlled exposure to perfume. Of the 42 individuals tested, 10 had more eye symptoms (irritation, itching, and tears) during perfume exposure than during placebo exposures, and eight of these individuals (P = 0.07, Fisher's exact test) belonged to the patient group. A true positive eye reaction to perfume was significantly associated with identification of perfume as an active exposure (P < 0.05). In this study, vapor of perfume elicited irritation in the eyes independently of olfaction, but the relative importance of ocular chemoperception in relation to elicitation of respiratory symptoms from common environmental exposures to perfume remains unclear. We investigated the hypothesis of an association between respiratory symptoms related to perfume and ocular perfume sensitivity by exposing the eyes to perfume in a double blind, placebo-controlled experiment. Vapors of perfume provoked symptoms in the relevant eye in some patients and healthy control persons, but under our exposure conditions, ocular chemesthesis failed to elicit respiratory symptoms.

Adult↗

Airborne chemicals cause respiratory symptoms in individuals with contact allergy.

Exposure to fragrance chemicals causes various eye and airway symptoms. Individuals with perfume contact allergy report these symptoms more frequently than individuals with nickel allergy or no contact allergies. However, the associations between contact allergy and respiratory symptoms elicited by airborne chemicals other than perfumes are unclear. The study aimed to investigate the association between eye and airway symptoms elicited by airborne chemicals (other than perfumes) and contact allergy in a population-based sample. A questionnaire on respiratory symptoms was posted, in 2002, to 1189 individuals who participated in 1997/1998 in a Danish population-based study of allergic diseases. Questions about eye and airway symptoms elicited by different airborne chemicals and airborne proteins were included in the questionnaire. Data from the questionnaire were compared with data on patch testing and prick testing. Having at least 1 positive patch test (adjusted odds ratio 1.7, 95% CI 1.2-2.5) was associated with the symptoms, and the odds ratio increased with the number of positive patch tests (P-value for test for trend <0.05). Bronchial hyperreactivity, female sex and psychological vulnerability were independently associated with symptoms, but no association was found between prick test reactivity to proteins and the symptoms elicited by airborne chemicals.

Adult↗

Mucosal symptoms elicited by fragrance products in a population-based sample in relation to atopy and bronchial hyper-reactivity.

BACKGROUND: Exposure to perfume and fragrance products may, in some individuals, cause symptoms from the eyes and airways. The localization, character and risk factors of such symptoms in the general population are unknown. OBJECTIVE: To investigate both the localization and character of symptoms from the eyes and airways elicited by fragrance products, and the associations between such symptoms and skin prick test reactivity (atopy), methacholine bronchial hyper-reactivity (BHR), allergic rhinitis and asthma. METHODS: A questionnaire on mucosal symptoms elicited by fragrance products was posted to 1189 persons who had participated in a Danish population-based study of allergic diseases in 1997/1998. The study included measurement of BHR, atopy, forced expiratory volume in 1 s (FEV1), and serum eosinophilic cationic protein (serum ECP). RESULTS: The response rate was 79.6%. Symptoms from the eyes or airways elicited by fragrance products were reported by 42%. BHR (adjusted odds ratio 2.3, 95% confidence interval 1.5-3.5) was independently associated with symptoms from the eyes and airways elicited by fragrance products. There were no significant associations between these symptoms and atopy, FEV1 or serum ECP. CONCLUSIONS: Mucosal symptoms from the eyes and airways were common in this population. BHR was a significant and independent predictor of these symptoms. The lack of association with atopy suggested that IgE-mediated allergic mechanisms do not play a major role in the development of these symptoms.

Asthma↗

Diagnosis of Hymenoptera venom allergy.

The purpose of diagnostic procedure is to classify a sting reaction by history, identify the underlying pathogenetic mechanism, and identify the offending insect. Diagnosis of Hymenoptera venom allergy thus forms the basis for the treatment. In the central and northern Europe vespid (mainly Vespula spp.) and honeybee stings are the most prevalent, whereas in the Mediterranean area stings from Polistes and Vespula are more frequent than honeybee stings; bumblebee stings are rare throughout Europe and more of an occupational hazard. Several major allergens, usually glycoproteins with a molecular weight of 10-50 kDa, have been identified in venoms of bees, vespids. and ants. The sequences and structures of the majority of venom allergens have been determined and several have been expressed in recombinant form. A particular problem in the field of cross-reactivity are specific immunoglobulin E (IgE) antibodies directed against carbohydrate epitopes, which may induce multiple positive test results (skin test, in vitro tests) of still unknown clinical significance. Venom hypersensitivity may be mediated by immunologic mechanisms (IgE-mediated or non-IgE-mediated venom allergy) but also by nonimmunologic mechanisms. Reactions to Hymenoptera stings are classified into normal local reactions, large local reactions, systemic toxic reactions, systemic anaphylactic reactions, and unusual reactions. For most venom-allergic patients an anaphylactic reaction after a sting is very traumatic event, resulting in an altered health-related quality of life. Risk factors influencing the outcome of an anaphylactic reaction include the time interval between stings, the number of stings, the severity of the preceding reaction, age, cardiovascular diseases and drug intake, insect type, elevated serum tryptase, and mastocytosis. Diagnostic tests should be carried out in all patients with a history of a systemic sting reaction to detect sensitization. They are not recommended in subjects with a history of large local reaction or no history of a systemic reaction. Testing comprises skin tests with Hymenoptera venoms and analysis of the serum for Hymenoptera venom-specific IgE. Stepwise skin testing with incremental venom concentrations is recommended. If diagnostic tests are negative they should be repeated several weeks later. Serum tryptase should be analyzed in patients with a history of a severe sting reaction.

Allergens↗

A link between skin and airways regarding sensitivity to fragrance products?

BACKGROUND: Exposure to volatile fragrances is commonplace and may be related to various eye and airway symptoms. Skin exposure to fragrances is known to cause perfume contact allergy and eczema, but it is unknown whether eye or airway symptoms elicited by fragrance products are associated with contact allergy or eczema. OBJECTIVES: To investigate if eye and airway symptoms elicited by fragrance products are associated with perfume contact allergy or hand eczema in a population-based sample. METHODS: A questionnaire on eye and airway symptoms elicited by fragrance products was mailed to 1189 individuals who had recently participated in a Danish population-based study of allergic diseases. Results from the questionnaire about localization and character of the symptoms were compared with data on patch testing and 1-year prevalence of hand eczema collected during the health examination. RESULTS: Positive, independent and significant (P < 0.05) associations were found between eye and airway symptoms elicited by fragrance products and perfume contact allergy (adjusted odds ratios 2.0-3.7) and hand eczema (adjusted odds ratios 1.6-2.6). In further analysis, similar and consistent results were found regarding severity of the symptoms. No associations were found between nickel contact allergy and the symptoms. Female sex and psychological vulnerability were independently associated with eye and airway symptoms elicited by fragrance products, but adjustment in multivariate analysis did not change the results regarding perfume contact allergy and hand eczema. CONCLUSIONS: Individuals with perfume contact allergy and/or hand eczema, as opposed to those without, have more frequent and more severe eye or airway symptoms after exposure to volatile fragrance products. Having hand eczema has the greatest impact on reporting eye and airway symptoms elicited by fragrance products.

Adult↗

House dust mites and their allergens at selected locations in the homes of house dust mite-allergic patients.

BACKGROUND: Knowledge of the occurrence of house dust mites (HDM) and their allergens in domestic locations is important when planning intervention. OBJECTIVE: The aim of this study was to describe the distribution of HDMs and their allergens before intervention in multiple locations in the homes of newly diagnosed HDM-allergic patients with a known high Der 1 concentration in their mattress dust. METHODS: Dust was collected from ten locations in the homes of eight HDM-allergic patients. Dust was analysed for allergen content with ELISAs for Der f 1, Der p 1 and Der m 1; and HDM were counted. Total allergen concentrations ( micro g Der 1/g dust) were expressed as the sum of Der f 1, Der p 1 and Der m 1. RESULTS: On mattresses the median concentration was 86 micro g Der 1/g dust (range 30-288) and 188 mites/g dust (range 12-1910). Der 1 exceeded 10 micro g/g dust in mattresses (8/8), duvets/pillows (3/8), a bedroom carpet (1/1), a living room carpet (1/6), upholstered furniture (2/8) and a curtain (1/5). Uncarpeted floors, upholstered furniture, bookshelves and walls had significantly lower Der 1 concentration than the mattresses. The relative contribution of Der p 1, Der f 1 or Der m 1 to Der 1 was related to homes, rather than to the location. Der m 1 only occurred in minute amounts. CONCLUSION: For HDM intervention, our results indicate that priority should be given to the removal of allergens from mattresses, and in addition from carpets, duvets/pillows and upholstered furniture. Dust from walls, uncarpeted floors, bookshelves and curtains appear to contribute insignificantly to the domestic HDM allergen load.

Animals↗

Allergen-specific immunotherapy in birch- and grass-pollen-allergic rhinitis. I. Efficacy estimated by a model reducing the bias of annual differences in pollen counts.

BACKGROUND: Evaluation of the efficacy of allergen-specific immunotherapy (IT) with pollen extracts is complicated by annual variation in pollen intensity. Our study aimed to evaluate the efficacy of birch and grass IT, taking into consideration these variations. METHODS: After 1 year of observation, 52 patients with rhinoconjunctivitis and allergy to birch as well as grass pollen were allocated to double-blinded clustered IT with aluminum-adsorbed extract produced from either birch (Betula verrucosa) pollen or grass (PIleum pratense) pollen. After 1 year of treatment, the patients continued IT with their original extract and also received the other extract. During the three consecutive pollen seasons, the rhinoconjunctivitis symptom score and the use of antihistamines, eye-drops, and oral prednisolone were recorded. Longitudinal data analysis was used to investigate the relation between different pollen counts and the magnitude of clinical efficacy. RESULTS: An effect of IT was found on symptom score, antihistamine intake, and eye-drop use for both birch and grass (P values <0.05). The mean reduction in symptom score/medication by IT ranged from 24% to 95%, depending on mean seasonal pollen counts. A minimum mean seasonal grass-pollen count of 20-30 pollen grains m3 was required for the efficacy of grass IT to emerge. CONCLUSIONS: A model was developed for evaluation of efficacy in longitudinal IT studies, taking the differences in annual pollen counts into consideration. The model showed a significant beneficial role of pollen IT in rhinoconjunctivitis patients allergic to birch and grass pollen.

Adolescent↗

Allergen-specific immunotherapy in birch- and grass-pollen-allergic rhinitis. II. Side-effects.

BACKGROUND: Allergen-specific immunotherapy (IT) involves the risk of side-effects. Different side-effect profiles have been reported for different allergens, and it would be of great benefit to be able more precisely to predict patient- and allergen-related risk factors. METHODS: Fifty-two patients with rhinoconjunctivitis and allergy to birch as well as grass pollen participated in a 3-year IT study, with a baseline year followed by 2 years of treatment. During the first treatment year, the patients received double-blinded IT with either birch (Betula verrucosa) or grass (Phleum pratense) pollen extracts adsorbed to aluminum hydroxide. The following year, the other allergen extract was added. Assessment of systemic reactions (SRs) was performed, and related to patient pretreatment parameters such as seasonal symptoms and medication requirement, skin prick test (SPT), conjunctival provocation test (CPT), nasal provocation test (NPT), total and specific IgE, basophil histamine release (HR), eosinophil count (EOS), eosinophil cationic protein (ECP), and eosinophil protein X (EPX). RESULTS: In total, 44 and 47 patients started IT with birch- and grass-pollen extracts, respectively. All SRs occurred during the dose-increase phase. No life-threatening SRs were observed. There were a higher number of patients with SRs during IT with grass pollen than IT with birch pollen, 21 vs five patients (P<0.001), with SRs to 3.3% of grass-pollen injections compared to 0.7% of birch-pollen injections (P<0.0001). The SRs of birch-pollen IT were mild, consisting of rhinoconjunctivitis and oral-pharyngeal itching, whereas asthma and urticaria episodes were observed in the grass-pollen IT. No difference was found in sensitivity to birch and grass, when measured by SPT, CPT, NPT, specific IgE, or HR, and no difference was found in age, duration of allergic symptoms, prevalence of asthma, mean seasonal birch/grass symptom score, eye-drop use, or antihistamine or prednisolone intake between the group with and without subsequent SRs to IT. No difference was found in EOS, serum ECP, or EPX, between the group with and without subsequent SRs to IT. CONCLUSIONS: IT with grass-pollen extract seems to be associated with a higher number and more severe SRs than birch-pollen IT. Neither demographic data nor diagnostic tests of allergy such as specific IgE, HR, SPT, CPT, and NPT could identify the patients with subsequent SRs.

Adult↗

Side-effects of insect venom immunotherapy: results from an EAACI multicenter study. European Academy of Allergology and Clinical Immunology.

BACKGROUND: The effect of venom immunotherapy (VIT) is well documented, but fear of systemic side-effects (SE) may prevent its use. The study aimed to analyze the character and frequency of SE and risk factors. METHODS: In a prospective study, 19 European centers included patients starting on VIT for systemic reactions to insect stings. Various dose regimens were applied. RESULTS: Data from 840 patients with a total of 26 601 injections were obtained. Seventy-one percent were treated with Vespula-venom extract and 27% with honeybee-venom extract. Twenty percent of patients had SE corresponding to 1.9% of injections during dose increase and 0.5% during the maintenance phase. The vast majority of the 280 reactions were mild: only one-third required medical treatment. Injected or inhaled adrenaline was applied in six patients, of whom only one had a drop in blood pressure and collapse. Female sex, bee-venom extract, and rapid dose increase, but not severity of insect sting reactions, increased the risk of SE. The severity of SE was less in males but was not related to age, treatment phase, species of insect, or severity of insect sting reactions. CONCLUSIONS: The frequency of SE was low, and the majority of these could be managed without treatment. Risk was increased in females, in bee-venom-treated patients, and in those with rapid dose increase.

Adolescent↗

[Allergy to dust mites].

House dust mites are the most important indoor allergens in our region. During recent years more dwellings have become infested, most likely as a result of increased indoor humidity due to reduced ventilation. Among Danish adults, 14% have developed IgE against mites. The allergens are stable and can remain for years. Keeping the humidity low (< 45%) during winter months is the most important limiting factor for mite growth. It can be accomplished by ventilation and heating. If bedding, pillow, eiderdown and covering mattress are washedat temperatures > 55 degrees C mites are killed and allergens removed. In addition mattress covers seem to be useful, although guidelines for quality assessment are lacking. Reduction in mite exposure will reduce development of allergy in all age groups especially in the newborn period. Immunotherapy can be offered in rhinitis and moderate asthma when sufficient allergen reduction cannot be accomplished.

Adult↗

[House dust mite allergens and mite allergy in Copenhagen dwellings. A cross-sectional study].

The aim of the study was to investigate the influence of various environmental factors on occurrence of house dust mite allergens and the influence of allergen exposure on mite allergy. Ninety-two persons from a population study filled in a questionnaire, were skin prick and lung function tested and dust samples were collected from their mattresses for analyses. Two out of five patients with asthma had a positive skin reaction to house dust mite allergen in contrast to five out of 87 non-asthmatics. Fifty-nine per cent of the dust samples contained (group 1) mite allergen > 2 micrograms/g dust. Such mattresses were older (median 7 years, range 1-22) than mattresses with less allergen (median 4 years, range 1-20). In the six bedrooms reported to be humid or mouldy, mattresses contained high concentration of mite allergens. No other parameter investigated could predict the allergen contents. In almost all cases dust analyses are crucial to be able to advise patients with house dust mite allergy.

Air Pollution, Indoor↗

Effect of two different types of vacuum cleaners on airborne Fel d 1 levels.

BACKGROUND: Vacuum cleaners may increase the level of airborne allergens by leakage through the cleaners or by disturbance of floor dust by the exhaust air produced. OBJECTIVE: The aim of this study was to evaluate the short-term effect of vacuum cleaning with two different types of cleaners on airborne cat allergen analyzed by a biologic and by an immunochemical test. METHODS: Ten homes with cats were cleaned in random order with a 1-week interval by a traditional canister type vacuum cleaner (T) and a semi-stationary vacuum cleaner (S) that conducts the air to the exterior through a valve in the wall. Airborne particles were collected by air sampling for 2 hours and cat allergen, Fel d 1, was quantified biologically by basophil histamine release test (HR test) and immunochemically by enzyme linked immunosorbent assay (ELISA). RESULTS: Using the S resulted in smaller amounts of airborne cat allergen than the T (mean 2.1 ng/m3 air (range .8 to 12.5) versus 5.2 ng/m3 (1.3 to 13.3), P < .002 measured by ELISA). Results from ELISA and HR test correlated well (r = .91, P < .001). CONCLUSIONS: The use of S with exhaust to the outside of the dwelling gave rise to less airborne low particle size allergen during the cleaning procedure than a T method. The basophil histamine release test could be a valid alternative method to establish allergen content in environmental samples especially in allergen systems with no available monoclonal antibodies.

Air Pollutants↗

Skin symptoms in patients with atopic dermatitis using enzyme-containing detergents. A placebo-controlled study.

Detergent enzymes may cause skin irritation and occasionally hypersensitivity reactions. The potential hazards of these enzymes have led some physicians to advise atopic dermatitis patients against the use of enzyme-enriched detergents. A three-phased randomised, double-blind, cross-over experiment was designed to question this recommendation. Each period was of 1 month's duration. In the first phase patients continued using their normal washing detergent. In phase II patients used trial detergent with or without added enzymes, and during phase III patients were given the opposite trial detergent. A total of 25 patients completed the study. The primary efficacy parameters were inter-period changes in corticosteroid usage and changes in SCORAD. Secondary efficacy parameters were altered subjective symptoms scored during the final 2 weeks of each interval. Analyses of all data revealed no statistical differences in any of the primary or secondary parameters comparing treatment and placebo periods. Our data therefore seem to exclude that atopic dermatitis may exacerbate during 1 month's exposure to enzyme-enriched detergents. Since no significant irritant capacity was detected in atopic dermatitis patients, it is unlikely that consumers with "normal skin" will experience any skin discomfort when enzyme-enriched detergents are used.

Adolescent↗

Exposure chamber for allergen challenge. A placebo-controlled, double-blind trial in house-dust-mite asthma.

Exposure chambers have proven to be valuable tools in the study of reactions to aeroallergens, and in monitoring the efficacy of antiallergic therapy. In the present study, 15 house-dust-mite-allergic asthmatics and five nonallergic volunteers were challenged in a recently developed exposure chamber. The trial was performed double-blinded with house-dust-mite allergen or placebo. Patients with allergy to house-dust mite (Dermatophagoides pteronyssinus) (Der p) were included by positive skin prick test, allergen-specific IgE, and conventional bronchial allergen challenge, with nebulizer and mouthpiece. In the exposure chamber, a total allergen dose corresponding to 1200 ng Der p 1 was applied. All participants kept diaries, recording peak expiratory flow rates, symptoms, and medication in periods of at least 2 weeks before and after each challenge. Twelve of the 15 asthmatics reacted with asthmatic symptoms with a median change in FEV1 of -16.4% when exposed to the allergen, but not to placebo, in the exposure chamber. Three patients had only minor symptoms during both chamber exposures and experienced no impairment of pulmonary function. Late-phase reactions were less frequent (one vs three) after the exposure chamber challenges, as compared to the traditional challenges. None of the healthy subjects reacted to the challenges. In conclusion, our exposure chamber was able to elicit symptoms in allergic subjects, and this ability was obtained with only minor amounts of house-dust-mite allergen. The described method could prove to be a more physiologically relevant model to monitor individual responses to aeroallergens.

Adolescent↗