Mechanisms by Which Atopic Dermatitis Predisposes to Food Allergy and the Atopic March

The Atopic march denotes the progression from atopic dermatitis (AD) to the development of other allergic disorders such as immunoglobulin (Ig) E-mediated food allergy, allergic rhinitis and asthma in later childhood. There is increasing evidence from prospective birth cohort studies that early-onset AD is a risk factor for other allergic diseases or is found in strong association with them. Animal studies now provide mechanistic insights into the pathways that may be responsible for triggering the progression from the skin barrier dysfunction seen in AD to epicutaneous sensitization, food allergy and allergic airway disorders. Recent large randomized controlled trials have demonstrated the efficacy of early interventions targeted at AD and food allergy prevention. These show great promise for research into future strategies aimed at prevention of the atopic march.

TSLP Polymorphisms in Atopic Dermatitis and Atopic March in Koreans

BACKGROUND: Atopic march (AM) is the progression from atopic dermatitis (AD) to allergic rhinitis and asthma. The development of AD is as high as 20% in children worldwide and continues to increase. AD seems to be caused by both genetic and environmental factors. Recently, polymorphisms of the thymic stromal lymphopoietin (TSLP) gene associated with allergic disorders were reported in ethnic groups from various countries. OBJECTIVE: Identification of TSLP polymorphisms in Koreans with AD or AM. METHODS: Whole-exome sequencing was performed in 20 AD and 20 AM patients. RESULTS: Nine single nucleotide polymorphisms (SNPs) of TSLP were detected (rs191607411, rs3806933, rs2289276, rs2289277, rs2289278, rs139817258, rs11466749, rs11466750, rs10073816). These SNPs have been correlated with susceptibility to allergic diseases in ethnic groups from China, Japan, Turkey, and Costa Rica in previous studies. Remarkably, one of 20 patients in the AD group lacked all SNPs, compared to six of 20 patients in the AM group. Odds ratios showed that Korean patients without the nine TSLP variants had an 8.14 times higher risk of moving from AD to AM. Two haplotype blocks were validated in 60 AD and 59 AM patients using Sanger sequencing. The haplotype blocks (rs3806933 and rs2289276) and (rs11466749 and rs11466750) were in high linkage disequilibrium, respectively (D′=0.97, D′=1). CONCLUSION: The increase of major allele frequency of respective nine TSLP variants may enhance the risk of AM. These data will contribute to improved genetic surveillance system in the early diagnosis technology of allergic disease.

Characteristics of Atopic Dermatitis in a Post-childhood Atopic March Group / 대한피부과학회지

BACKGROUND: Little knowledge is available on the characteristic differences between patients with atopic dermatitis (AD) with and without atopic march after childhood. OBJECTIVE: To observe and compare the phenotypes of patients with AD in regards to atopic march tendency at a single point. METHODS: We enrolled patients with AD aged between 10 and 30 years. The patients were divided into the atopic march and non-atopic march groups on the basis of an investigator-designed survey questionnaire, and their serum-specific immunoglobulin E (IgE) levels or results of the skin prick test were compared. RESULTS: In a total of 182 patients enrolled in the study, 93 patients with atopic march and 89 patients with non-atopic march were observed. When their serum-specific IgE levels or results of the skin prick test were compared between the two groups, there was no significant difference, except for a in the atopic march group. Analysis of AD severity, family history of allergic diseases, and total IgE levels between the two groups showed no statistically significant differences. CONCLUSION: Our findings suggest that although no apparent phenotype characteristics could differentiate the presence of atopic march, the history of the patient's allergic diseases should be revalidated, and clinicians should watch out for future developments of atopic march when a patient shows a high-class sensitization rate to dust mite.

The Atopic March: Progression from Atopic Dermatitis to Allergic Rhinitis and Asthma

Atopic dermatitis (AD) is an inflammatory disease characterized by pruritic skin lesions. The pathogenesis of AD may include disrupted epidermal barrier function, immunodysregulation, and IgE-mediated sensitization to food and environmental allergens. AD is also part of a process called the atopic march, a progression from AD to allergic rhinitis and asthma. This has been supported by multiple cross-sectional and longitudinal studies and experimental data. Research on the mechanisms of AD has been centered on the adaptive immune system with an emphasis on the T-helper 1 (Th1)-Th2 paradigm. Recently, the conceptual focus has largely shifted to include a primary defect in the epithelial barrier as an initial event in AD providing a significant insight into the disease initiation and pointing to a complex secondary interplay of environmental and immunological sequelae with barrier disruption. Further understanding of AD will help the development of more effective treatment for AD and ultimately, preventative algorithms for the atopic march. In this review we highlight recent advances in our understanding of the pathogenesis of AD and the atopic march.

Marcha atópica / Atopic march

Objetivo: Rever a literatura a respeito do conceito de marcha atópica, suas bases teóricas e evidências clínicas. Tal conhecimento é importante no entendimento e aplicação dos princípios de prevenção primária e secundária das doenças atópicas. Fontes dos dados: Pesquisa bibliográfica em base eletrônica de dados, limitando a busca a artigos publicados nos últimos 15 anos, referentes a pesquisas ou estudos clínicos em seres humanos e estudos experimentais, escritos em português ou inglês. Referências a livros pertinentes ao tema também foram incluídas. Foram selecionados os artigos mais citados e com metodologia e discussão melhor estruturados dentro do tema dermatite atópica / marcha atópica. Síntese dos dados: O conceito de marcha atópica é uma tentativa de se explicar a inter-relação entre as doenças atópicas, assim como as características da história natural de cada uma delas. Tal conceito baseia-se em estudos clínicos que demonstraram que, em cerca de 50% dos indivíduos predispostos, as doenças atópicas ocorrem de forma seqüencial, sendo a dermatite atópica considerada como o primeiro passo desta marcha. Conclusões: A partir de dados coletados em estudos sobre prevalência de doenças atópicas e os possíveis fatores determinantes envolvidos no desenvolvimento das mesmas, princípios de prevenção primária e secundária podem ser recomendados e implementados.

Objective: To review the literature on atopic march concept, its theoretical basis and clinicai evidences. This knowledge is important to understand and to apply the principies of primary and secondary atopic diseases prevention. Data sources: A bibliographic search was done in electronic database, limited to articles published in the last 15 years, related to human research or experimental research, written in Portuguese or English. Some book relevant references were also included. The articles about atopic dermatitis and atopic march were selected according to the number of citation and the better methodology and discussion. Data synthesis: The atopic march concept is a trial to explain the relationship between the atopic diseases and the natural evolution of each one. Clinicai researches have demons¬trated that in something about 50% of predisposed individual, the atopic diseases occurred in a sequence way, being the atopic dermatitis the first step in this marcho Conclusions: Principies of primary e secondary prevention can be recommended and implemented after review the data collected in studies about prevalence of atopic diseases and the factors involved in the development of such diseases.