Atopic dermatitis: pathogenetic mechanisms

Abstract

Atopic dermatitis (AD) is a chronic inflammatory skin disease with increasing incidence and socio-economical relevance. The diagnosis is made on clinical grounds and different diagnostic criteria sets have been established. The majority of all AD cases is associated with a sensitization to environmental allergens and increased serum IgE (so-called extrinsic AD), but about 10--30% of all cases suffer from the so-called intrinsic AD, which obviously lacks any link to the classical atopic diathesis. The genetic background of AD has been investigated by target gene approach by different groups with mostly contradictory results for each of the genes under study. An imbalance in the spectrum of Th1/Th2 responses, a disturbed prostaglandin metabolism, intrinsic defects in keratinocyte function, delayed eosinophil apoptosis, IgE-mediated facilitated antigen presentation by epidermal dendritic cells, a two phase model of the inflammatory response and staphylococcal superantigen effects are among the currently studied pathogenetical aspects of extrinsic AD, which are reviewed in this paper.

The Interleukin-13 Production by Peripheral Blood T Cells from Atopic Dermatitis Patients Does Not Require CD2 Costimulation

“…Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease characterized by typically distributed eczematous skin lesions with lichenification, pruritic excoriations, dry skin, and susceptibility to cutaneous infections [1, 2]. As the name implies, AD is considered to be an atopic disease.…”

Charmadala: A Contribution of Kashyapa in Childhood Skin Disease

“…Atopic dermatitis is notorious for its recalcitrance and tendency to chronic recurrence and can lead to significant morbidity, social isolation and emotional stress. There is increasing evidence that the prevalence of atopic dermatitis in children has increased over the past 30 years 13,14 , although the reasons for this increase are unknown. The current prevalence is estimated to be 10.0% to 15.6%.…”

“…Atopic dermatitis clearly has a hereditary basis 15,14,18 . The eczema is triggered or exacerbated by interactions between a genetic predisposition and environ-mental factors 14,18 .…”

“…Atopic dermatitis clearly has a hereditary basis 15,14,18 . The eczema is triggered or exacerbated by interactions between a genetic predisposition and environ-mental factors 14,18 . The environmental factors include (a) physical factors like sweating, climate, warm surroundings, detergents and soap, synthetic or woollen fabrics, cigarette smoke, (b) psychological factors, (c) food items (including tomato, orange and citrus fruits, juice from meat, fish) (d) allergens such as house dust mite, animal hair, pollen, plants and others such as Staphylococcus aureus and release of exotoxins (superantigens) and saliva in small children 18,20 …”

Atopic Dermatitis and Fungi

“…Antigen presented by these cells may stimulate Th2 cells to synthesize IgE and hence contribute to the inflammatory changes in the skin (22,80,92). When the skin of patients with AD is examined, it is often drier than the skin of an individual without AD (146,164). It also reacts differently in response to stimulation.…”