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

Gut Microbiota, Probiotics, and Their Interactions in Prevention and Treatment of Atopic Dermatitis: A Review

Atopic dermatitis (AD) is a public health concern and is increasing in prevalence in urban areas. Recent advances in sequencing technology have demonstrated that the development of AD not only associate with the skin microbiome but gut microbiota. Gut microbiota plays an important role in allergic diseases including AD. The hypothesis of the “gut-skin” axis has been proposed and the cross-talk mechanism between them has been gradually demonstrated in the research. Probiotics contribute to the improvement of the intestinal environment, the balance of immune responses, regulation of metabolic activity. Most studies suggest that probiotic supplements may be an alternative for the prevention and treatment of AD. This study aimed to discuss the effects of probiotics on the clinical manifestation of AD based on gut microbial alterations. Here we reviewed the gut microbial alteration in patients with AD, the association between gut microbiota, epidermal barrier, and toll-like receptors, and the interaction of probiotics and gut microbiota. The potential mechanisms of probiotics on alleviating AD via upregulation of epidermal barrier and regulation of immune signaling had been discussed, and their possible effective substances on AD had been explored. This provides the supports for targeting gut microbiota to attenuate AD.

Atopy patch testing with aeroallergens in a large clinical population of dermatitis patients in Germany and Switzerland, 2000-2015: a retrospective multicentre study

BACKGROUND

The diagnostic significance of the atopy patch test for the management of dermatitis possibly triggered by aeroallergens is still controversial. However, sufficiently large studies with routinely tested standardized aeroallergen patch test preparations in dermatitis patients are lacking.

OBJECTIVE

To evaluate the reaction frequency and the reaction profiles of 10 until mid-2015 commercially available, standardized aeroallergen patch test preparations of the 'Stallerpatch' test series (Stallergenes, Antony Cedex, France) in a large multicentre patient cohort.

METHODS

A retrospective data analysis of patients with suspected aeroallergen-dependent eczematous skin lesions was performed, who were patch tested in 15 Information Network of Departments of Dermatology-associated clinics between 2000 and 2015. Patients were stratified according to their atopic dermatitis (AD) status.

RESULTS

The study group included 3676 patients (median age 41 years, 34.8% males, 54.5% AD). The most common aeroallergens causing positive patch test reactions were Dermatophagoides pteronyssinus (19.6%), Dermatophagoides farinae (16.9%), birch (6.2%), timothy grass (6.0%), cat dander (5.4%), mugwort (4.9%) and dog dander (4.6%). Reactions to other pollen allergen preparations, that is 5 grasses (3.2%), cocksfoot (2.1%) and plantain (1.6%), were less common. Positive patch test reactions to aeroallergens were consistently more frequent in patients with AD. These patients showed proportionally less dubious, follicular, irritant and weak positive reactions. Independent of AD status, a patient history of past or present allergic rhinitis was associated with an increased chance of a positive aeroallergen patch test reaction to pollen allergens.

CONCLUSION

The aeroallergen patch test is a useful add-on tool in clinical routine, especially in patients with AD and/or respiratory allergy. A patch test series comprising Dermatophagoides pteronyssinus, Dermatophagoides farinae, birch, timothy grass, cat dander and mugwort seems to be suitable. Controlled studies with specific provocation and elimination procedures are required to further evaluate the diagnostic significance of the proposed screening series.

Atopy patch test in children with atopic dermatitis

BACKGROUND

Atopic dermatitis is frequently associated with food and/or aeroallergen allergy.

OBJECTIVE

To evaluate atopy patch tests (APTs) and skin prick tests (SPTs) in children with atopic dermatitis, using allergen extracts from locally lyophilized foods (cow's milk, egg white, egg yolk, wheat, soy, and shrimp), Dermatophagoides pteronyssinus, Dermatophagoides farinae, and American cockroach.

METHODS

This study was a prospective, self-controlled study in children with atopic dermatitis. APTs, SPTs, and oral food challenge tests were performed in the cases with written informed consent.

RESULTS

Fifty-six children with atopic dermatitis were enrolled. According to the Severity Scoring of Atopic Dermatitis Index, moderate atopic dermatitis was the most common severity (49.1%) followed by mild (20%) and severe atopic dermatitis (13.2%). APT results were positive for food allergens in 49% of participants; SPT results were positive in 54.7%. The sensitivity, specificity, positive predictive value, and negative predictive value of APTs for foods were 40%, 90.2%, 65.2%, and 76.6%, respectively. For SPTs, those values were 40%, 93.9%, 75%, and 77.3%, respectively. APT results for D farinae, D pteronyssinus, and American cockroach were positive in 33.9%, 35.8%, and 21.8% of participants, respectively. SPT results for these allergens were positive in 28.3%, 24.5%, and 9.4% of participants, respectively. No serious complications occurred.

CONCLUSION

APTs with locally prepared lyophilized allergen extracts were safe and had high specificity, median positive predictive value, and low sensitivity for evaluation of suspected food allergy in children with atopic dermatitis.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01164293.

Identification of allergens by IgE-specific testing improves outcomes in atopic dermatitis

INTRODUCTION

IgE quantitative assaying of allergens (IgEQAA) has long been implemented by allergists in determining patients' reactivities for allergic rhinitis and asthma, two of the three diagnoses in atopic syndrome. This test operates by measuring the patient's IgE response to different allergens and can identify potential triggers for a patient's symptoms. Despite this, IgEQAA has yet to see the same widespread use in the field of dermatology, specifically in the treatment of patients with atopic dermatitis (AD).

MATERIALS AND METHODS

The affected body surface area (BSA) at first presentation, IgEQAA classes, and total immunoglobulin E (IgE) concentration were taken retrospectively for 54 patients with AD.

RESULTS

Of the 54 patients observed, 41 had an abnormally high total IgE concentration (76%). Additionally, it was observed that nine (17%) of our patients significantly improved after making lifestyle changes.

CONCLUSION

Knowledge of the identified specific antigens can guide patients to make lifestyle modifications that may improve disease outcomes. IgEQAA and avoidance of allergens may help some patients with AD.

Avaliação do teste de contato com aeroalérgenos em pacientes com dermatite atópica

FUNDAMENTOS: a dermatite atópica é uma doença inflamatória cutânea que apresenta múltiplos fatores desencadeantes. Há vários relatos de autores que confirmaram os aeroalérgenos como fatores agravantes ou desencadeantes. O teste de contato com aeroalérgenos ou teste de contato atópico foi proposto para avaliar a participação destes alérgenos na dermatite atópica. OBJETIVO: objetivo deste estudo foi avaliar a positividade do teste de contato atópico em pacientes com dermatite atópica. MÉTODOS: Avaliamos 50 pacientes com dermatite atópica e 45 do grupo com rinite alérgica, nos quais realizamos teste de contato atópico com extratos de Dermatophagoides pteronissynus, Dermatophagoides farinae e Blomia tropicalis, além de testes cutâneos de leitura imediata para os mesmos alérgenos, acrescidos de epitélio de cão e gato e fungos. RESULTADOS: verificamos que o teste de contato atópico com ácaros apresentou maior positividade nos indivíduos do grupo de dermatite atópica quando comparado ao grupo de rinite alérgica. CONCLUSÕES: o teste de contato atópico apresenta resultados estatisticamente significativos quando realizado com ácaros, em pacientes com dermatite atópica, com p=0,035, OR (odds ratio) = 3,35 e IC(95%) = [ 1,18; 9,47].

The diagnostic value of atopy patch testing and prick testing in atopic dermatitis: facts and controversies

We conducted a systematic Medline search of the literature (1998-2008) on the criteria for performing the skin prick test and atopy patch testing (APT) to determine their utility in atopic dermatitis (AD). The skin prick, scratch, and skin patch tests are performed to identify which allergen is causing eczematous skin symptoms in patients with AD, or sneezing, nasal congestion, itchy eyes, wheezing, skin rash, and swelling. Many allergens in foods, drugs, and environmental substances (eg, ragweed and fungus), as well as contact allergens, can elicit eczematous skin reactions after epicutaneous application. Because no gold standard exists for aeroallergen provocation in AD, the APT is currently used to evaluate allergen without comparison with another accurate and reliable method. The APT is presumed to reflect delayed-phase clinical reactions. Even with delayed onset of symptoms (more than 2 hours after food ingestion), APT findings were not consistent among AD children. The APT could be used in children with gastrointestinal reactions to foods as well as AD. After standardization, the APT may provide further diagnostic information in addition to the skin prick test and serum immunoglobulin E values and may be able to evaluate the actual clinical relevance of immunoglobulin E-mediated sensitizations for eczematous lesions. The European APT model used with standardization of allergen concentration and vehicle may provide an important diagnostic tool to select patients for avoidance and for procedures of allergen-specific immunotherapy, but the clinical relevance of positive APT reactions awaits standardized provocation and avoidance testing.