Atopic Dermatitis: Global Epidemiology and Risk Factors

Abstract

Fifty percent of all those with atopic dermatitis develop other allergic symptoms within their first year of life and probably as many as 85% of patients experience an onset below 5 years of age Key insights Atopic dermatitis often begins in early childhood and is the first Key WordsAtopic dermatitis · Atopic march · Skin barrier defect · Immune dysregulation · Genetics · Environment Abstract Atopic dermatitis (AD) is a chronic inflammatory skin disease posing a significant burden on health-care resources and patients' quality of life. It is a complex disease with a wide spectrum of clinical presentations and combinations of symptoms. AD affects up to 20% of children and up to 3% of adults; recent data show that its prevalence is still increasing, especially in low-income countries. First manifestations of AD usually appear early in life and often precede other allergic diseases such as asthma or allergic rhinitis. Individuals affected by AD usually have genetically determined risk factors affecting the skin barrier function or the immune system. However, genetic mutations alone might not be enough to cause clinical manifestations of AD, and it is merely the interaction of a dysfunctional epidermal barrier in genetically predisposed individuals with harmful effects of environmental agents which leads to the development of the disease. AD has been described as an allergic skin disease, but today, the contribution of allergic reactions to the initiation of AD is challenged, and it is proposed that allergy is rather a consequence of AD in subjects with a concomitant underlying atopic constitution. Treatment at best achieves symptom control rather than cure; there is thus a strong need to identify alternatives for disease prevention. • AD usually starts in early childhood and can be the initial step of the so-called 'atopic march'.• The prevalence of AD is as high as 20% in children in some countries and continues to increase, affecting now not only developed countries but also lowincome countries.• AD is a complex disease, and the relationship between allergy and AD (allergy being a cause and/or an exacerbating factor of AD) is still debated.• Genetics has recently been shown to be an important risk factor for AD, and the strongest association so far with the gene encoding filaggrin has raised the recent interest in the role of skin barrier impairment in the development of AD.• Environmental factors and specifically exposure to microbes are also recognized to play a role in the development of the disease.• AD is a multifactorial disease presenting with different endophenotypes.• The prevention of AD should start as soon as possible (possibly even in utero), targeting both skin barrier, immune/allergy and environmental aspects.

Prevalence of Severe Atopic Dermatitis in Adults in 3 Areas of Spain

“…In addition, the waxing and waning nature of the signs and symptoms, the fact that severity is rarely substantially modified for a single patient, and a possible bias in disease classification could, to our understanding, lead us to underestimate severe cases. Considering the comorbidities (Table), our results seem to be in accordance with available data [2,9,10].…”

“…It affects 10%-20% of children, the most prevalent form being chronic disease, and 1%-3% of adults, particularly in the most developed Western societies [1][2][3]. Fifty percent of cases resolve during adolescence, with up to 20% of cases persisting into adulthood and a prevalence of 1%-3% in patients aged more than 60 years [4].…”

Environmental risk factors and their role in the management of atopic dermatitis

“…The prevalence of AD has increased over the past several decades in virtually every country worldwide, with continued increased still being observed in some countries [164]. The rapidly increasing global prevalence cannot be attributed to genetics alone, suggesting that environmental exposures may be triggering and/or flaring disease in predisposed individuals.…”

Рівень Сироваткового Еотаксину Як Маркер Тяжкості Атопічного Дерматиту В Дітей Раннього Віку

“…Атопічний дерматит (АтД) -це хронічне запаль-не захворювання шкіри, що вражає до 20 % дітей, але останні дані показують, що його поширеність продовжує зростати, особливо в країнах із низьким рівнем доходу [1]. Це суттєво знижує якість життя пацієнтів і створює значне навантаження на ресур-си системи охорони здоров'я [2,3].…”