Diagnostic Work-up and Treatment of Severe and/or Refractory Atopic Dermatitis

Atopic dermatitis (AD) or atopic eczema , is a chronic inflammatory skin disease characterized by dry skin, itching and recurrent red and scaly skin lesions. It is a relatively common skin disease with an estimated prevalence of 10-20%. The majority of patients show their first clinical symptoms in infancy or early childhood, with reported percentages of 60% before the age of 1 year and 85% before the age of 5 year. The pathogenesis of AD is characterized by a complex interaction between a genetic background and different environmental factors. Over the last years genome wide linkage mapping as well as selective region specific linkage mapping based on candidate genes, has revealed many possible AD related loci on different chromosomes. Summarizing there seem to be two major groups of genes present within the genetic background of AD: genes encoding for epidermal or other epithelial structural proteins and genes encoding for major elements of the immune system. The term “atopic dermatitis” was coined by Wise and Sulzberger in 1933 and reflects the association between AD and other so-called atopic disorders, such as asthma and allergic rhinitis. The diagnose is based on clinical criteria, with the extensive criteria of Hanifin and Raijka as the classical starting point published in 1980. In the years to follow several modifications were proposed, leading to publications on different new sets of criteria. For our own research purposes we currently use the diagnostic criteria formulated by the UK working party on AD, which have been extensively validated in the past and are widely accepted as a diagnostic tool (figure 1).