The non-atopic (intrinsic) eczema

Atopic dermatitis (AD) is a chronic relapsing, inflammatory skin disease, caused by a genetic predisposition and a variety of environmental triggers. In most cases, AD is linked to a specific IgE immune response to common inhalants or food allergens and therefore classified as an atopic subtype, the so-called atopic eczema (AE). However, in up to 30% of patients with AD, there are normal serum IgE levels and negative skin tests; as a result, the term non-atopic eczema (NAE) has been proposed to replace the otherwise used terms intrinsic or non-IgE-associated form of AD. Facing this constellation, solely atopy patch tests, which elicit eczematous skin reactions after epidermal application of common aeroallergens, may indicate a putative role of local T cell response in the skin and, thus, are highly important in NAE. Next to a certain genetic disposition, infectious triggers and autoreactivity in patients with NAE have been observed. In the following, we will present a short overview to highlight typical characteristics in NAE and possible pathogenic factors in this AD subtype.