Effect of house dust mite avoidance measures in children with atopic dermatitis

BACKGROUND: House dust mite allergens are associated with atopic dermatitis (AD). OBJECTIVES: The aim of our study was to verify if house dust mite allergen avoidance measures can improve the clinical manifestations of AD in children. METHODS: Forty-one children (mean age 3.9 years) affected by AD associated with high total and/or specific IgE serum levels ('extrinsic' AD) were recruited. Clinical evaluation was performed utilizing the Severity Scoring of AD (SCORAD) index; dust was sampled from the children's beds and tested using an enzyme-linked immunosorbent assay. The study was planned in two parts. In the first part, a placebo-controlled trial of 2 months duration, mite allergen avoidance measures (encasing mattresses and pillows; a weekly hot wash of bedding; frequent vacuum cleaning of living room and bedroom; soft toys and carpets regularly cleaned or removed; no pets allowed) were recommended to group A patients, but not to group B. In the second part of the study, environmental avoidance measures were recommended to initial control group B patients also. One year after the start of the study the amounts of mite allergen in the home and clinical score of AD were measured in both groups. RESULTS: At the end of the first part of the study, significant decreases in major allergens of Dermatophagoides pteronyssinus (Der p1) and D. farinae (Der f1) load (from 393 to 94 ng m-2) and concentration (from 1.84 to 0.73 microg g-1 of dust) in children's beds were observed in treatment group A. At the same time, in this group the mean SCORAD index improved significantly (from 33 to 26; P = 0.022). After 12 months, when all patients had used allergen avoidance measures, Der p1 + Der f1 load, concentration and clinical score had improved, reaching similar values in both groups. CONCLUSIONS: Simple mite allergen avoidance measures should be recommended to families with children affected by extrinsic AD in order to control the clinical manifestations and prevent mite sensitization.     

Improvement of atopic dermatitis and reduction of skin allergic responses by oral intake of konjac ceramide

Although topical application of ceramide is effective in the treatment of atopic dermatitis, its effect is transient. Thus, the effect of oral intake of ceramide on atopic dermatitis was studied. Two groups of 25 children with moderate atopic dermatitis, who were allergic to house dust mite took either milk sugar (control group) or 1.8 mg/day of konjac ceramide in milk sugar (ceramide group) once a day for 2 weeks. Before and after 2 weeks, skin symptoms were assessed using the SCORAD index, while allergic skin responses to house dust mite were assessed by skin prick test. Moreover, production of allergen-specific IgE and various cytokines by mononuclear cells was measured. After 2 weeks, SCORAD index score, allergic skin responses to house dust mite and house dust mite-specific IgE production were significantly reduced in the ceramide group, but not in the control group. Moreover, house dust mite-induced cytokine production was skewed towards the Th1 type, since production of Th1 cytokine, IFN-gamma, and IL-12, was increased, while production of Th2 cytokine, IL-4, and IL-13, was decreased. In contrast, no change of these parameters was found in control group. Collectively, oral intake of konjac ceramide improved skin symptoms and reduced allergic responses with concomitant skewing of the cytokine pattern towards the Th1 type.     

Can atopy patch tests with aeroallergens be an additional diagnostic criterion for atopic dermatitis?

The complex pathomechanisms underlying skin lesions in atopic dermatitis (AD) result in variations of the clinical picture and frequent diagnostic difficulties. The purpose of this study was to evaluate the usefulness of atopy patch tests (APT) for aeroallergens in the diagnosis of AD. The study involved 115 adult patients with AD and 98 healthy volunteers (the control group). APTs for cat dander allergens, birch pollen, a mixture of house dust mite species and a mixture of 5 grass pollen allergens were applied for both groups. Positive reaction to at least one test allergen was found in 53.9% patients compared to 6.2% in the control group (p<0.001). The most frequent hypersensitivity (45.2%) observed was to house dust mite allergens. Polyvalent allergy to 2-4 allergens was found in 56.5% patients. The specificity of tests exceeded 75%, whereas the sensitivity varied from 18 to 66%. CONCLUSIONS: 1. Atopy patch tests, which are characterised by considerable specificity, confirm the role of polyvalent contact hypersensitivity to aeroallergens in the development of atopic dermatitis. 2. Positive aeroallergen ATP results are observed in the majority of patients and can thus be regarded as an additional diagnostic criterion in atopic dermatitis.     

Atopic dermatitis and house dust mites

The occurrence of house dust mites (Dermatophagoides spp) was investigated in the homes of 26 patients with atopic dermatitis (AD), 20 patients with psoriasis and 41 randomly selected homes in Arhus, Denmark. The AD patients with moderate to severe eczema had an increased concentration of mites (median 85 mites/0.1 g mattress dust) compared with the controls (median 8 mites/0.1 g mattress dust). The higher exposure to house dust mites corresponded to a relative risk of 4.6 and a clear dose-response relationship between exposure and disease could be demonstrated. Our results illustrate a clear association between moderate to severe atopic dermatitis and increased exposure to house dust mites in the patients' homes, and support the hypothesis that mite antigens could be an aetiological factor in atopic dermatitis.     

Active participation of eosinophils in patch test reactions to inhalant allergens in patients with atopic dermatitis

Intracutaneous testing and patch tests with house dust mite and grass pollen allergens were performed in patients with atopic dermatitis. Only patients with an immediate type skin reaction to house dust mite or grass pollen allergens showed a positive patch test reaction to these allergens 24-48 h after testing. Occasionally positive patch test reactions at 20 min, 2 h and 6 h were also observed. Patch test reactions were not found in normal controls or atopic patients without atopic dermatitis. Analysis of the cellular infiltrate demonstrated an influx of eosinophils into the dermis, starting from 2-6 h after patch testing. Immunostaining with antibodies against granular constituents of the eosinophils revealed that the infiltrating eosinophils were in an activated state and had lost part of their granular contents. At 24 h eosinophils also appeared in the epidermis. Electron microscopy showed that in the epidermis, some eosinophils were in close contact with Langerhans cells, suggesting a cell-cell interaction. Taken together, these results strongly suggest an active role for eosinophils in patch test reactions to inhalant allergens in atopic dermatitis patients.     

Atopy patch testing with aeroallergens in patients with atopic dermatitis and controls in Singapore

The role of allergy in atopic dermatitis is controversial. The atopy patch test (APT) has been used to investigate the association between atopic dermatitis and aeroallergen allergy. To determine the proportion of patients with atopic dermatitis with positive patch tests to common local aeroallergens and to compare this to controls with and without respiratory atopy, we performed APT, skin-prick tests (SPT) and IgE radioallergosorbent tests (RAST) on 73 patients with atopic dermatitis and on 38 nonatopic controls (13 with and 25 without respiratory atopy). The allergens used were house dust mite, cat dander, Bermuda grass and German cockroach. Only the APT for house dust mite showed a significant difference between the two groups. APT for house dust mite correlated with the RAST test, while APT for cat fur correlated with the SPT. The APT may be useful to evaluate aeroallergens in atopic dermatitis, but further work is needed to make it more reliable.     

Reduction of environmental mites improved atopic dermatitis patients with positive mite-patch tests.

During a series of studies on the involvement of house dust mite antigens in 183 cases of atopic dermatitis, we observed an improvement in two patients following the removal of mites from their environment by means of a thorough housecleaning and replacement of the mattress. Both patients manifested the typical clinical skin lesions of atopic dermatitis and had similar laboratory findings. Although the serum IgE concentrations and specific IgE to Dermatophagoides pteronyssinus and Dermatophagoides farinae were each relatively low, the results of patch tests with these antigens were positive. Thus, a regimen aimed at reducing the presence of house dust mites can produce clinical improvement in a subset of patients with atopic dermatitis who show contact hypersensitivity to mite antigens on skin testing, but negative results on IgE (RAST; radioallergosorbent technique) testing.     

The relationship between eosinophils, OKT6-positive cells and house dust mite (HDM) antigens in naturally occurring lesions of atopic dermatitis.

To determine the role of eosinophils in naturally occurring lesions of atopic dermatitis, we observed the distribution of eosinophil cationic protein (ECP) and the relationship between eosinophils, OKT6-positive cells and house dust mite (HDM) antigens. Some specimens showed many EG2-positive stains, although the accumulation of tissue eosinophils was not prominent. EG2 stains were seen not only in eosinophils but also in extracellular granules. Some macrophage-like cells of the dermis showed EG2 stains in the form of phagocytized eosinophil granules. Some EG2-positive eosinophils were in close contact with OKT6-positive cells in the epidermis and dermis. Furthermore, in three patients sensitive to house dust mite (HDM) antigen, HDM antigens invaded the skin with many EG2-positive stains. These results suggest that eosinophils play an active role in the development of eczematous lesions of atopic dermatitis.     

儿童期特应性皮炎145例临床分析

目的探讨儿童期特应性皮炎(AD)患儿临床特征及常见特异性变应原分布。方法回顾性分析2013年7月-2014年7月在湖南省儿童医院皮肤科门诊就诊的145例儿童期AD患儿的临床资料,总结其性别比例、地域、加重季节、临床表现及血清特异性变应原分布等特征。结果 145例患儿年龄2~12岁,66.9%有过敏性疾病家族史,其中以过敏性鼻炎(40.7%)最为常见。居住在城市患儿明显高于农村,两者间比值为1.7:1;皮损加重季节以夏、秋季为主,占63.4%。根据AD评分(scoring atopic dermartitis,SCORAD)标准,中度儿童期AD患儿多见(61.4%),且男童比女童较为严重,差异有统计学意义(P<0.05)。血清特异性IgE以吸入性过敏原为主(61.5%),其中户尘螨、粉尘满、屋尘最为常见。结论儿童期AD患儿城市多于农村,常夏秋季节加重,男患儿皮损较女患儿严重,多并发过敏性鼻炎,过敏原以吸入性变应原为主。     

House dust mites on skin, clothes, and bedding of atopic dermatitis patients

Background  Atopic dermatitis is a common allergic condition in children, often associated with a positive skin reaction to house dust mite allergens.
Aim  To determine the presence of house dust mites on the skin, clothes, and bedding of patients with atopic dermatitis.
Methods  Nineteen patients with atopic dermatitis were examined during a 2-year period. Samples from affected and healthy skin surfaces were obtained with adhesive tape, and dust samples from bedding and clothes were collected with a vacuum cleaner at the start of the study and 3–6 weeks later, and examined for the presence of house dust mites. The findings were compared with those of 21 healthy controls.
Results  The most common mite species on skin were Dermatophagoides pteronyssinus and Dermatophagoides farinae , which were found in nine patients and three controls. The patient group showed a significantly larger percentage of samples with mites than did the control group (34.9% and 7.9%, respectively) ( P  < 0.001), and a significantly larger percentage of individuals with at least one positive sample (84.2% and 14.2%, respectively) ( P  < 0.0001). No correlation was found between the number of mites on the skin and clothes/bedding of patients, or between patients and controls with regard to the number of mites on the clothes and bedding.
Conclusions  Patients with atopic dermatitis showed a higher prevalence of mites on their skin than did healthy individuals, which could be involved in allergic sensitization and disease exacerbation.     

Evaluation of RAST in atopic dermatitis

Eighty-two patients with atopic dermatitis were examined for specific IgE antibodies by RAST. A higher number of positive RAST reactions were found in patients with high serum IgE values and with coexisting asthma and/or allergic rhinitis. Positive RAST reactions against mite and house dust were found in many of these patients and even in about one-half of patients with atopic dermatitis only. The comparisons between intradermal tests and RAST were made with various allergens and the mite extract showed the best agreement between these two tests.     

特应性皮炎和慢性荨麻疹患者皮肤点刺试验检查结果分析

目的:了解皮肤点刺试验对特应性皮炎和慢性荨麻疹患者的临床意义。方法:对进行皮肤点刺试验的33例特应性皮炎和20例慢性荨麻疹患者的结果进行总结分析。结果:在特应性皮炎和慢性荨麻疹患者中均以粉尘螨(分别为78.79%,75.00%)和屋尘螨(分别为75.76%,70.00%)的阳性率最高,粉尘螨和屋尘螨在两者中的阳性率比较,差异均有统计学意义(χ2=9.04,P<0.05;χ2=12.35,P<0.05)。牛奶在慢性荨麻疹患者中的阳性率(30.00%)高于在特应性皮炎患者中的阳性率(6.06%),差异有统计学意义(χ2=8.00,P<0.05)。结论:特应性皮炎患者较慢性荨麻疹患者对粉尘螨、屋尘螨更易过敏,而后者较前者对牛奶更易过敏。进行皮肤点刺试验可以有效寻找过敏原,减少病情反复机会。     

816例皮肤点刺试验过敏原结果分析

目的 探讨特应性皮炎、慢性荨麻疹、慢性湿疹常见过敏原的可能致病情况.方法 用标准变应原液在前臂屈侧皮肤进行皮肤点刺试验,分别用0.1%组胺和0.9%氯化钠液作阳性和阴性对照,统计分析采用x2检验.结果 尘螨(屋尘螨+粉尘螨)的阳性率最高,达50.0%～78.6%,其次为动物毛,达7.1%～21.4%,霉菌的阳性率也较高,达7.1%～14.3%,并且这3种变应原在3种疾病间的阳性率差异均有统计学意义(P＜0.01),以特异性皮炎的阳性率最高.食物组过敏原中虾的阳性率(6.6%～14.3%)最高,但在3种疾病间的阳性率差异无统计学意义(P＞0.05);金枪鱼在慢性荨麻疹中的阳性率(9.5%)较高,鸡蛋、牛奶、芹菜在特异性皮炎中的阳性率(7.1%～14.3%)较高,这4种变应原在3种疾病间的阳性率差异均有统计学意义(P＜0.05).结论 吸入组过敏原是慢性过敏性皮肤病的常见过敏原,尘螨为首要过敏原,以特异性皮炎的阳性率为最高.     

Sensitization to cockroach allergens evaluated by skin tests in children with atopic dermatitis

INTRODUCTION: Cockroach and house dust mites (Dermatophagoides pteronyssinus, Dp and farinae, Df) are the most often implicated aeroallergens in severe asthma, hay fever and conjunctivitis. Cockroach allergy is still unknown in atopic dermatitis.PATIENTS AND METHOD: 146 children with atopic dermatitis-aged 6 months to 15 years- have been patch tested with the European standard series and some aeroallergens. We have studied the sensitisation to cockroach allergens and compared to Dp and Df.RESULTS: 113 children reacted positively at least to one of the 3 aeroallergens (77 p. 100), 61 children had a positive reaction to cockroach (42 p. 100) and 29 simultaneously to the 3 allergens.DISCUSSION: Delayed hypersensitivity to house dust mites in young children with atopic dermatitis suggests early epicutaneous sensitization due to an altered epidermal barrier. For us, cockroach could also be implicated in some flare-ups of atopic dermatitis. Eviction of cockroach and house dust mite should be proposed for children with a positive patch test to cockroach.     

Comparison of different activity parameters in atopic dermatitis: correlation with clinical scores

BACKGROUND: Several laboratory markers have been described to correlate positively with disease activity of atopic dermatitis (AD). These include soluble adhesion molecules and eosinophil granular proteins. Although the correlation of these parameters with the severity and extent of skin involvement has been repeatedly studied in the past, no systematic investigation has been performed over a lengthy period of time. In addition, no subjective disease parameters recorded by the patient have been included in studies dealing with disease activity. OBJECTIVES: To assess the validity of different objective and subjective parameters [soluble E-selectin (sE-selectin), soluble vascular cell adhesion molecule-1 (sVCAM-1), eosinophil cationic protein (ECP), urinary nitrate excretion (reflecting endogenous nitric oxide formation) and the patients' impressions of pruritus, sleeplessness and skin status] as markers of AD disease activity. METHODS: Twenty patients were examined for 1 year and their skin status was evaluated by an established score (SCORAD). sE-selectin, sVCAM-1 and ECP were analysed by commercial test kits. Urinary nitrate concentration was measured by gas chromatography-mass spectrometry. The subjective parameters, pruritus, sleeplessness and impression of skin status, were recorded by the patients on a visual analogue scale. RESULTS: In this long-term trial, only sE-selectin and the subjective parameters showed a statistically significant correlation with the SCORAD score. CONCLUSIONS: Our data indicate that basic clinical scoring remains a most effective and relevant method of recording skin disease activity in AD.     

THE ROLE OF MITE,HOUSE DUST AND CANDIDA ALLERGENS IN CHRONIC URTICARIA

Intradermal skin tests and in vitro antigen-induced histamine release from leucocytes were carried out using mite, house dust and candida allergens in 49 patients with chronic urticaria in whom the cause was not identifiable from the history. None of them had other atopic diseases. Among the 49 cases, the number of patients who gave positive skin reactions to different allergens was as follows: mite, 24; house dust, 18; candida, 17. Significant histamine release from leucocytes by mite antigen was observed in 8 out of 12 patients who had 2+ or 3+ skin reactions. The present results suggest that mite, house dust and candida allergens may play a role in chronic urticaria, and especially that the mite may be one of the possible allergens in chronic urticaria.     

Patch tests with house dust mite antigens in atopic dermatitis patients: methodological problems.

Patch tests with house dust mite allergens were performed in 21 atopic dermatitis patients with a positive prick test and RAST for house dust mite. Variables in methodology of patch testing, i.e. allergen concentration, application time, and intensity of tape stripping, were studied. Tests were performed with Dermatophagoides pteronyssinus solutions containing 20X, 100X and 500X the prick test concentration and purified HDM antigen: 10 and 50 micrograms/ml P1Ag solution. The series was applied on 8X or 15X tape-stripped and clinically normal skin on the back during 24 and 48 h. Non-specific reactions due to tape stripping, fixation tape or patch test occlusion were frequently observed: after 15X tape-stripping in 3/7 (24-h application) and 6/7 (48-h application) patients, after 8X tape-stripping in 2/19 (24-h application) and 8/19 (48-h application) patients. Reactions clinically assessed as specific occurred in 6/21 (29%) atopic dermatitis patients, 4/6 occurring in the 10 patients with a serum IgE greater than 1000 kU/l. High allergen concentrations and 48 h of application increased the number of patients with specific reactions. If 15X tape-stripping had been omitted, 2/3 patients tested in this manner and showing specific test reactions would have been negative. Further conclusions regarding the value and the preferable method of patch testing with atopic allergens require an in vitro control test.     

Atopy patch test reaction to airborne allergens in the diagnosis of atopic dermatitis

The aim of the study was to evaluate the possible use of atopy patch test in the diagnosis of atopic dermatitis and to characterize an optimal standardized system for atopy patch test in terms of allergen concentrations and time of allergen exposure. The study included 36 patients with atopic dermatitis and IgE-mediated airborne allergy. Patients presented positive results of skin prick tests and serum antigen specific IgE against house dust mite allergens and/or selected grass pollen allergens. Control groups consisted either of patients with allergic rhinitis (control group 1) or healthy volunteers with no signs or symptoms of atopy (control group 2). Allergologic diagnostic workup consisted of skin prick test, serum antigen specific IgE and total IgE evaluation, atopy patch test with selected airborne allergens of different concentrations (0.1xSPT, 1xSPT and 10xSPT), time of allergen exposure (8, 24 and 48 h), and readings of the results (8, 24, 48 and 72 h). Positive results of atopy patch test with airborne allergens were obtained in 47.2% of atopic dermatitis patients and none of control subjects. Contact reaction itself and the intensity of reaction were demonstrated to correlate with allergen concentration and time of allergen exposure on atopy patch test. The dose and time response analysis showed the optimal concentration of allergens for atopy patch test to be 10xSPT, 500000 SBE/ml, and optimal evaluation time 24 and 48 h of allergen application. There was no correlation between atopy patch test results and mean serum concentrations of total or antigen specific IgE. Atopy patch test results did not correlate with localization of skin lesions, severity and extensiveness of skin inflammation. A significantly higher contact reactivity to airborne allergens was recorded in the group of atopic dermatitis patients with polyvalent allergy in comparison with atopic dermatitis patients allergic to only one aeroallergen. It is concluded that atopy patch test is the only provocation test currently available with clinical relevance for contact IgE-mediated sensitization in atopic dermatitis patients. Using petrolatum as a vehicle, allergen concentration of 500000 SBE/ml and evaluation time of 24 and 48 h of allergen application may lead to improved atopy patch test results.     

A randomized trial of leukotriene receptor antagonist montelukast in moderate-to-severe atopic dermatitis of adults

Leukotriene receptor antagonists are recommended for the treatment of asthma, and have proved anecdotally successful even in atopic dermatitis. Standard treatments of atopic dermatitis are often unsatisfactory. Accordingly, we compared montelukast, 10 mg/day, with a combined regimen (orally administered cetirizine and clarythromycin, topical corticosteroids and hydrating preparations) for treatment of moderate-to-severe atopic dermatitis of adults. The trial was designed as a randomized single-blind study. SCORAD, eosinophilic cationic protein (ECP), eosinophilic protein X (EPX) serum levels were assessed at baseline and after 6 weeks in 32 adult patients with atopic dermatitis (16 treated with montelukast; 16 treated with the combined regimen). Similar improvements, evaluated in term of SCORAD reductions, were detected in both groups (Mann-Whitney, p < 0.05), while ECP and EPX levels significantly reduced within each group (Welch's approximate t, p < 0.05). We conclude that montelukast is as effective as the comparison combined regimen to treat atopic dermatitis of adults.     

Atopy patch test reactions to house dust mites in patients with scabies

It is well known that the house dust and the scabies mites are related phylogenetically. We therefore performed atopy patch tests with house dust mite antigens (Dermatophagoides pteronyssinus (Dp) and/or Dermatophagoides farinae (Df)) in scabies patients without atopy and healthy controls. We studied 25 men with active scabies and 25 healthy controls. Skin prick tests with standardized house dust mite extract were performed for all patients and controls. An intradermal test procedure was carried out in skin prick test-negative patients, and for controls showing positive atopy patch test to Dp and/or Df. While atopy patch tests were performed directly in all healthy controls, patients with scabies were first treated and on the next day, atopy patch tests were performed. Twenty-two of 25 patients with scabies (88%) had skin prick test and/or intradermal test positivity against house dust mites, whereas 17/25 patients (68%) had atopy patch test positivity against house dust mites (Dp and/or Df). There was no statistically significant difference between skin prick test and/or intradermal test positivity and atopy patch test positivity in a regression analysis (p=0.222). The only statistically significant correlation was between atopy patch test positivity and the extent of scabies involvement (p<0.05). Only few of the healthy controls had positive tests. In this study, we have shown that a positive atopy patch test to house dust mite antigens is not specific for patients with atopic dermatitis, but also occurs in scabies patients without a history of atopic dermatitis.