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Atopic dermatits in infants and children in Israel: clinical presentation, allergies and outcome.

BACKGROUND: Atopic dermatitis is a common disease in infants and children and the incidence appears to be rising. OBJECTIVES: To determine the presentation, allergies, and outcome among Israeli infants and children. METHODS: Children with atopic dermatitis referred to the allergy clinic at a regional pediatric center were evaluated for their medical history and their allergy. The allergic assessment was determined by utilizing skin prick tests and/or serum specific immunoglobulin E concentrations. The children were reexamined again for all parameters at the end of the follow-up period. RESULTS: Forty-six children with atopic dermatitis were studied, 27 males (58.7%) and 19 females (41.3%). A family history of allergy was found in 19 (41.3%). The median age at presentation was 17 months. Of the 46 children 33 (71.7%) revealed an allergy to one or more of the allergens. The most common combination was allergy to food and house-dust mites. The mean follow-up time was 64 months. By the age of 8 years full recovery was seen in 16 patients, half of whom recovered within 3.3 years from the date of presentation. The probability of complete remission was 58%, and for either complete or partial remission 76%. Upon reevaluation at the end of the follow-up period some patients lost their sensitivities, while others, who had been allergic to foods, became sensitive to house-dust mites and/or pollens. CONCLUSIONS: Atopic dermatitis is an allergic problem in the northem region of Israel, as it is in other parts of the world. Food allergy and house-dust mites are major contributors to the evolution of eczema.

Child↗

Allergy to house dust mites and asthma.

House dust mites have been shown to be important sources of indoor allergens associated with asthma and other allergic conditions. Asthma is a chronic respiratory disease that affects millions of people worldwide, and numerous scientific studies have shown that the prevalence of asthma is increasing. The most common dust mite species around the world include Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), Euroglyphus maynei (Em) and Blomia tropicalis (Bt). Over the past three decades, many important allergens from these species have been identified and characterized at the molecular level. The biological function of several house dust mite allergens has been elucidated, with many of them showing enzymatic activity. However, Bt allergens remain the least studied, even though this mite is very common in tropical and subtropical regions of the world, including Puerto Rico. Therefore, it is very important to include Bt in diagnostic and therapeutic strategies for house dust mite induced allergy and asthma, particularly in areas where Bt exposure and sensitization is high. Recombinant DNA technology, as well as other molecular biology and immunological techniques, have played a fundamental role in advances towards a better understanding of the biology of house dust mites and their role in allergic diseases. This kind of study also contributes to the understanding of the complex immunologic mechanisms involved in allergic reactions. The development of effective diagnostic and therapeutic approaches depends on the continuity of research of house dust mite allergens. The objectives of this review are to describe the most important aspects of house dust mite allergy and to acquaint the scientific community with the latest findings pertaining to house dust mite allergens, particularly those derived from Bt.

Allergens↗

Skin test positivity to aeroallergens in the patients with chronic urticaria without allergic respiratory disease.

The etiology of chronic urticaria and angioedema remains uncertain in most of the patients. There are several agents and factors including medications, foods and food additives, infections, contactants, inhalants, physical factors and autoimmunity that implicated in provoking urticaria symptoms. In addition, the possible role of house dust mites has been considered in a few reports. We investigated skin test positivity to house dust mites and other inhalants in 259 patients with chronic idiopathic urticaria and angioedema but without allergic rhinitis and/or asthma. Results were compared with both 300 healthy controls and 300 atopic patients. Immediate cutaneous reactivity to one or more allergens was detected in 71 patients in the study group (27.4%). The most common allergens were house dust mites (24.7%). Skin prick test sensitivity to other inhalant allergens including pollens, molds and cockroach were 7.7%, 0.4% and 0.8%, respectively. In the healthy control group 7% of patients were found as atopic with respect to skin prick test results. The most common allergens in healthy controls were pollens (6%), and house dust mites (4.7%). In atopic control group, pollens and mites are also the most common allergens detected in skin prick test (62% and 50.3%, respectively). The difference between study and healthy control group was statistically significant with respect to presence of atopy and mite sensitivity (p < 0.001). Similar differences were not established in other inhalant allergens. Significant mite sensitivity in the study group is not a coincidence. Because, ratio of skin test positivity to house dust mites in the study group was higher than the healthy controls, but was not as high as atopic patients. Furthermore, the rate of skin reactivity to other aeroallergens was not different from healthy controls. Urticaria as a sole clinical manifestation in mite sensitive patients was unusual.

Adolescent↗

[Methods of detection of tick allergens in house dust].

Different detection methods of housing dust allergens (belonging to the tick species Dermatophagoides pteronyssinus, D. farinae) were considered. As shown in this study, the immunochemical method in combination with acarological analysis proved to be most promising. On the basis of the data on the cross activity of tick allergens and changes in their content in dust, grounds were given for the expediency of detection by the immunochemical method with the use of polyclonal antibodies to specially obtained immunogen.

Allergens↗

[Potential risk factors aggravating airway allergy--aspects of involvement of airtight housing and passive smoking].

OBJECTIVES: The involvement of tightly insulated housing conditions and passive smoking in atopic sensitization, a major risk factor for airway allergy, was examined with nonsmoking adult women and school-age children. SUBJECTS AND METHODS: The subjects were 382 nonsmoking healthy adult women (housewives) who underwent medical examinations for prevention of adult diseases conducted in a district of Osaka from 1995 to 1997, and 214 elementary school-children 9-12 years old living in an urban district of Osaka who underwent medical examinations at a health center in April, 2000 to prevent allergic diseases. We also examined the correlation between tightly insulated housing conditions and the amount of passive smoking based on family smoking habits with 170 children under 12 years old who had been under the care of a hospital pediatrics department between December, 1993 and May, 1994. A questionnaire was administered to all subjects to survey the housing structure (concrete/wooden housing), family smoking habits and visible mold proliferation in the kitchen in relation to airtight housing conditions, passive smoking and exposure to inhalant allergens. Atopic sensitization was assessed by positivity for serum house dust mite-specific IgE, and passive smoking was defined as a urinary cotinine level of more than 6 ng/mgCr. RESULTS: 1. Among the three factors, indoor mold proliferation and family smoking habits were positively and synergistically related with atopic sensitization to house dust mites. 2. Airtight conditions of concrete housing showed a promotional effect on passive smoking for housewives, but a suppressive effect for school-age children. 3. Taking into account the above results, the promotional effects of passive smoking on atopic sensitization appeared predominantly in the concrete housing-residence group of housewives and the wooden housing-residence group of school-age children. 4. Effects of visible mold proliferation in the kitchen on atopic sensitization appeared predominantly in wooden housing-residence group of housewives. CONCLUSIONS: The results suggest that involvement of the three factors in atopic sensitization is due to increased exposure to indoor inhalant allergens or enhanced IgE-antibody production (adjuvant effects of tobacco smoke) and the extent of their inpact varies depending on the individual life styles of the housewives and school-age children.

Adult↗

[Exposure and allergy to dust mites in general and working environment in Croatia].

This paper gives a review of the most important impacts of exposure to dust mites in general and working environment on human health. The Institute for Medical Research and Occupational Health in Zagreb, Croatia, has been investigating the frequency and exposure levels of allergies to pyroglyphid and non-pyroglyphid mites in Croatia for the last 10 years. Investigations were performed in general urban and rural population from the inland and coastal Croatia, and several industrial inland populations occupationally exposed to organic dusts. Mite species and levels of pyroglyphid mites allergens (Der p 1, Der f 1) were established in house dust samples taken from the floors of bedrooms and living rooms and in several industrial dust samples. The frequency of allergies to pyroglyphid mites in general urban population of inland Croatia is about 20%, with significant general indoor exposure to these mites (median value for Der p 1: 0.85 microg/g of dust). General adult population of the coastal region had a significantly higher exposure to pyroglyphid mites (median value for Der p 1: 4.5 microg/g of dust), yet showed a significantly lower frequency of allergies to these mites (about 5%). New studies are necessary to investigate possible genetic and environmental factors involved in the mechanisms which protect coastal population from the development of mite allergy. Acarological and statistical analyses have shown that the high frequency of sensitisation to non-pyroglyphid mites found in the general and working populations of the inland region is not related to environmental exposure to these mites, but to the cross-reactivity between pyroglyphid and non-pyroglyphid mites and to false positive skin reactions in prick testing, particularly to T. putrescentiae. So far, results do not indicate that pyroglyphid mites are occupational allergens in paper-recycling, fish-processing and tobacco-processing.

Allergens↗

Nasal provocation test (NPT) with isolated and associated dermatophagoides pteronyssinus (Dp) and endotoxin lipopolysaccharide (LPS) in children with allergic rhinitis (AR) and nonallergic controls.

BACKGROUND: Inhalation of endotoxin may enhance inflammatory airway response in sensitized asthmatics persons after allergen(s) inhalation. OBJECTIVE: To evaluate nasal response to intranasal instillation of Dermatophagoides pteronyssinus (Dp), endotoxin (LPS), and to Dp+LPS in children with perennial allergic rhinitis (PAR). METHODS: 10 PAR children (positive skin prick test to Dp) and 10 nonallergic controls (C) undergoing nasal provocation test (NPT), who were quantified by active anterior rhinomanometry and measurement of Total Nasal Resistance (TNR). The NPTs were initially performed with histamine (H; 0.03 to 16.0 mg/mL), and then, at least at weekly intervals, the NPTs were done with Dp (1/100,000 to 1/2.5), LPS (1 to 500 mg/mL) and to Dp+LPS. During NPT with Dp+LPS, Dp concentration was kept constant (1/100,000; 1/10,000; 1/1,000) and was combined with different concentrations of LPS (1, 5, 10, 20 mg/mL). The NPT was considered positive when TNR reached twice the basal TNR. RESULTS: H and Dp NPTs were positive in all AR children. In group C, H NPT was positive in 60% and Dp NPT was negative in all children. NPT with LPS was positive only in 30% of the AR children. NPT with Dp+LPS was positive in 90% of the AR patients in Dp concentration of 1/1,000 and in LPS concentrations of 5, 10, and 20 mcg/ mL. This positive association was observed with Dp concentrations lower than those obtained during NPT with Dp in 60% of AR patients. There were no changes in pulmonary function tests in all children after NPT. CONCLUSIONS: This study suggests that LPS enhances the effects of allergen challenges on nasal airflow. The daily inhalation of allergens plus endotoxin in AR patients does increase the nasal responsiveness.

Adolescent↗

A survey of acarofauna in Turkey: comparison of seven different geographic regions.

House-dust mites play an important role in allergic sensitization in Turkey and other countries. The purpose of this study was to analyze the acarofauna in seven zones that differ in climate and altitude. Dust mites were isolated in 173 of 930 (18.6%) samples. The highest prevalence of house-dust mites was found in the most humid regions of Turkey: Mediterranean (48.4%) and Black Sea (46%). Lower levels were found in central and eastern Anatolia regions where humidity and temperature are low. Mites of the Dermatophagoides spp. were predominant (D. pteronyssinus [83%] and D. farinae [12%] making up the majority of the counts). The presence of mites was related to an increase both in mean temperature (> 15 degrees C) and in humidity (> or = 40%) as well as low altitude (< 300 m). This study suggests that the mite population of humid coastal regions of Turkey is as prevalent as in other temperate climates.

Altitude↗

Quantitative expression of the major homing integrins alphaL and alpha4 on human cord blood hematopoietic progenitor and stem cells.

An increased traffic of hematopoietic progenitor cells (HPC) between bone marrow and peripheral organs is a peculiar feature of the allergic inflammation. It has been recently reported that the sublingual form of specific immunotherapy (SLIT) is capable of reducing such an increased HPC traffic. The House Dust Mite major antigen Der p1 has been proved to up-regulate the expression of the ICAM-1 and VCAM-1 endothelial addressins, supporting the view of an inflammatory cell recruiting at the site of allergen extract administration. In the present work we have investigated, by flow-cytometric techniques, the expression of the two major integrins CD11a (LFA-1) and CD49d (VLA-4) that are the homing receptor cognate for ICAM-1 and VCAM-1 on human cord blood CD34 hematopoietic progenitor and stem cells. Even if both the investigated molecules resulted detectable on CD34+ HPC surfaces, being the system redundant, the density of the cellular expression was significantly higher for CD49d (median value: 158) than CD11a (median value: 20.5), suggesting a preferential usage of the homing axis VLA-4/VCAM-1. Results consistency with outcomes of clinical trials that relate SLIT efficacy to allergen dosage is discussed.

Antigens, CD34↗

Measurement of nasal IgE in an epidemiological study: assessment of its diagnostic value in respiratory allergy.

BACKGROUND: Specific questionnaire and skin prick test (SPT) are the most used methods in epidemiological studies on respiratory allergy. SPT, however, can be positive in many subjects without evidence of any allergic disease. Nasal IgE determination has been suggested by some authors as a valuable diagnostic method, which may overcome this lack of specificity. OBJECTIVE: The aim of this study was to evaluate sensitivity and specificity of nasal specific IgE for the seven most common inhalant allergens in order to verify its reliability as a screening test. METHODS: 126 children, involved in an epidemiological study on prevalence of respiratory allergic disease, were evaluated. All children were assessed with a specific questionnaire, SPT and nasal specific IgE. Nasal specific IgE were determined with a previously described method modified for screening purposes, in order to test seven allergens at the same time. When discordant results were obtained between questionnaire, SPT and nasal IgE, an allergen specific nasal challenge (ASNC) was performed and nasal tryptase was also determined before and after challenge. RESULTS: The questionnaire was positive for respiratory allergy in 28/126 children. SPT was positive in 21 of the 28 children, but also in 5/10 children with atopic dermatitis (AD), and in 12/88 children without allergic symptoms. Nasal IgE were positive in 22/28 and also in 2/10 with AD. Nasal challenge and tryptase confirmed the negativity of nasal IgE in 12/17 children with positive SPT but totally negative for allergic respiratory disease. Moreover nasal IgE was found to be positive to dermatophagoides in one of seven children with negative SPT despite a clinical history suggestive for mite respiratory allergy. In this patient and in 2 of the 5 children with AD the positive nasal IgE to mites was confirmed by a positive ASNC and tryptase. CONCLUSIONS: Nasal IgE have shown a specificity significantly higher than SPT (98% vs. 83%) and a good sensibility. This screening test may also be useful to detect the beginning of upper airways sensitization in patients with AD.

Allergens↗

Cetirizine reduces cytokines and inflammatory cells in children with perennial allergic rhinitis.

Cetirizine has been demonstrated able of reducing nasal inflammatory infiltration in children with allergic rhinitis and cytokine production in in vitro studies. The aim of this double-blind, placebo-controlled, and randomized study was to evaluate cytokine pattern and inflammatory cells in children with perennial allergic rhinitis, before and after treatment with cetirizine or placebo. Twenty children with perennial allergic rhinitis were evaluated, 13 males and 7 females (mean age 13.4 years). Inflammatory cells and cytokines were evaluated by scraping and nasal lavage, before and after 2-weeks administration of cetirizine or placebo. IL4 and IL8 were measured by immunoassay and inflammatory cells were counted by conventional staining. Cetirizine treatment induced a significant decrease of IL4 (p<0.01) and IL8 levels (p=0.01). A significant reduction of the inflammatory cells was detected in actively-treated children, both concerning neutrophils and eosinophils (p<0.01). Moreover, cetirizine significantly reduced nasal obstruction score (p=0.007). This study shows the cetirizine effectiveness in exerting anti-inflammatory activity by modulating cytokine pattern and by reducing inflammatory infiltration in children with perennial allergic rhinitis.

Adolescent↗

House dust mite allergen levels in Chiang Mai homes.

The quantitative assays for house dust mite (HDM) allergens provide a valid index of exposure and can be used for risk evaluation. We assessed group I HDM allergen levels in mattress and living room floor dust from 35 Chiang Mai homes and identified factors associated with high allergen levels. One-third of mattress and living room floor dust had group I HDM allergen levels of between 2-10 microg/g. Two-thirds of mattress dust and a small amount of living room floor dust had group I HDM allergen levels of over 10 microg/g. The geometric means of Der p I, Der f I and total group I allergens in mattress and living room floor dust were 8.61, 2.88, and 15.81 microg/g and 1.61, 0.27 and 2.43 microg/g, respectively. Mattresses made of kapok and rugs kept in the living room were associated with high group I allergen levels.

Allergens↗

[A strategy for assessing environmental influence on airway allergy using a regression binary tree-based method].

OBJECTIVE: To clarify the living environment factors that increase the risk of allergic sensitization to house dust mites, we applied a regression binary tree-based method (CART, Classification & Regression Trees) to an epidemiological study on airway allergy. The utility of the tree map in personal sanitary guidance for preventing allergic sensitization was examined with respect to feasibility and validity. SUBJECTS AND METHODS: A questionnaire was given to 386 healthy adult women, asking them about their individual living environments. Also, blood samples were collected to measure Dermatophagoides pteronyssinus (Dp)-specific IgE, the presence/absence of Dp-sensitization being expressed as positive/negative. The questionnaire consisted of nine items on (1) home ventilation by keeping windows open, (2) personal or family smoking habits, (3) use of air conditioners in hot weather, (4) type of flooring (tatami/wooden/carpet) in the living room, (5) visible mold proliferation in the kitchen, (6) type of housing (concrete/wooden), (7) residential area (heavy or light traffic area) (8) heating system (use of unventilated combustion appliances), and (9) frequency of cleaning (every day or less often). There also were queries on the past history of airway allergic diseases, such as bronchial asthma and allergic rhinitis. CART and a multivariate logistic regression analysis (MLRA) were performed. The subjects were first classified into two groups, with and without a history of airway allergic diseases (Groups WPH and WOPH). In each group, the involvement of living environment factors in Dp-sensitization was examined using CART and MLRA. RESULTS: In the MLRA study, individual living environment factors showed promotional or suppressive effects on Dp-sensitization with differences between the two groups. With respect to the CART results, the two groups were first split by the factor that had the most significant odds ratio for MLRA. In Group WPH, which had a Dp-sensitization risk of 19.5%, the first split was by the factor of visible mold proliferation in the kitchen into the factor-present group with a risk value of 45.5% and the factor-absent group with 13.5%. The mold proliferation group was split with reference to frequent cleaning, and the risk rose to 75% in the factor-absent group and to 100% when family smoking habits were reported. Group WOPH (the risk: 10.8%) was first split into two groups according to the use of air conditioners in hot weather for more than 6 hours a day or less, which showed risk values of 16.7% and 6.9%, respectively. The risk of the group that intensively used air conditioners fell to 8.3% with tatami as flooring in the living room, and, if others, rose to 20.8%. The risk of the factor-lacking group fell to 4.0% without wooden flooring. CONCLUSIONS: CART analysis enables us to express complex relationships between living environment factors and Dp-sensitization simply by a binary regression tree, pointing to preventive strategies that can be flexibly changed according to the individual living environments of the subjects.

Environment↗

[Most common allergens in allergic patients admitted into a third-level hospital].

BACKGROUND: Since year 3000 BC, pollenology (science that studies allergens) was already known. In the year 49 BC, Herodotus recognized the first case of hay fever, Jacob Constant (17th century) described the first case of allergic rhinitis and related it to "something" (allergens) that roses emitted. Charles Backley (1873) proved the ability of the skin to determine allergic reactions to allergens. Today, it is well-known that allergens are able to react with environmental exposure, plants and pollens. OBJECTIVE: To know the most common allergens in allergic patients who are admitted into a tertiary care hospital. MATERIAL AND METHODS: 3,172 electronic expedients of registered allergic patients were examined. Only 356 fulfilled the inclusion criteria. Five groups of allergens were studied: group 1 (pollens), 2 (fungus), 3 (inhaled allergens), 4 (food) and 5 (other allergens), the value of seric IgE was registered too. RESULTS: The main allergens that were found are: 156 (43.8%) Amaranthus palmeri, 163 (45.5%) Candida albicans, 262 (73.6%) dust mite, 33 (9.3%) chicken and 4 (1.2%) apple/pineapple. The main diseases were: 254 (71.3%) allergic rhinitis, 52 (14.6%) asthma-rhinitis, 39 (11%) asthma and 63 (17.6%) others, the value of seric IgE was minimum of 1 and maximum of 9,620 Ul/dL. CONCLUSIONS: Allergens affecting patients are not different of what is reported in world-wide literature; however, it is of great significance to know this and take it as a guideline to achieve clinical improvement with the use of an appropriate immunotherapy.

Adolescent↗

Skin sensitization to common allergens in Turkish wheezy children less than 3 years of age.

Infants and small children with asthma are not commonly skin tested, as allergy is not considered to be a major cause of infantile asthma. The aim of this study was to determine the frequency of skin test positivity to various allergens in wheezy children less than 3 years of age. We evaluated 161 patients with infantile asthma (median age 20 months) and 100 healthy controls (median age 18 months). Infantile asthma was defined as three or more episodes of wheezing in a child less than 3 years of age, whose symptoms improved on treatment with beta-agonist and anti-inflammatory agents. All children were skin tested to house dust mites (HDM), pollens, molds, and cow milk extracts using prick technique. One hundred and eighteen (73.3%) children In the patient group tested positive to HDM, 84 (52.1%) to pollens, 37 (22.9%) to molds, and 16 (10%) to cow milk. Sensitization rates to HDM were significantly higher in the patient group than In the healthy controls. Sensitization rates to pollens were not statistically different between the two groups. There was no association between family history of atopy and frequency of sensitization to allergens in the wheezy and control groups. We concluded that skin sensitization to allergens was common In wheezy infants. The prevalence of sensitization to indoor allergens was higher than to outdoor or food allergens.

Allergens↗