Send Orders of Reprints at reprints@benthamscience.org 62 The Open Allergy Journal, 2012, 5, 62-64 1874-8384/12 2012 Bentham Open Open Access The Danish Atopy Database (DAD): Rationale and Methods Simon Francis Thomsen * , Jakob Mutanu Jungersted, Maja-Lisa Clausen and Tove Agner Department of Dermatology, Bispebjerg Hospital, Copenhagen, Denmark Abstract: Atopic dermatitis is a multifactorial chronic disease that poses a great burden for patients and society. In recent decades the prevalence has increased substantially in many countries, notably in Western societies, and the causes for this increase are not completely understood. There are still many unanswered questions regarding atopic dermatitis with re- spect to aetiology, pathophysiology, co-morbidity as well as subgrouping and treatment of the disease. Establishment of the Danish Atopy Database (DAD), a cohort with ongoing inclusion of outpatients with atopic dermatitis from a tertiary referral centre, allows the study of these aspects of the disease. Herein we present our methodological considerations in regards to establishment of this cohort. Keywords: Atopic dermatitis, database, methodology, outpatient, treatment. INTRODUCTION Atopic dermatitis (AD) is a chronic inflammatory skin disorder that affects around 20% of the population [1]. The disease is characterized mainly by the presence of dry itchy skin accompanied by chronic or relapsing eczema with an early onset primarily in individuals with a familial history of atopic disorders. In infancy, eczema typically develops on the face and scalp as well as on the extensor aspects of the arms and legs [2]; later in childhood flexural eczema occurs, whereas in adulthood skin changes are more often confined to the face and neck, as well as the hands, although some suffer from more widespread eczema [1]. In adults, hand eczema sometimes is the only symptom, which may however take a chronic course [3]. Widespread skin involvement usu- ally requires various treatments, including support of the psychological and socioeconomic aspects of the disease, and these patients are most often managed in hospital settings. However, in most patients the disease has a favourable prog- nosis; around 75% are symptom-free in adolescence and early adulthood. AD has a substantial heritable component, and suscepti- ble individuals react to environmental stimuli to develop manifest disease [4]. Immunologically, AD is characterised by activation of T helper type 2 cells with production of cy- tokines IL-4, 5 and 13, leading to excessive production of IgE. Another main problem in AD is a defective skin barrier leading to excessive water loss through the epidermis, and easy access for bacteria and viruses. Identification of muta- tions in the gene encoding filaggrin in patients with AD has renewed the interest for the skin barrier [5], and during the latest years much research within AD has focused on this. Skin emollients and topical corticosteroids are first line therapy for AD [6], while topical immunemodulators and *Address correspondence to this author at the Department of Dermatology, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark, Tel: +45 26139838; Fax: +45 35313950; E-mail: sft@city.dk UV-radiation are second line treatments [7]. Recalcitrant disease usually requires treatment with systemic immuno- suppressive drugs such as azathioprine, methotrexate, cy- closporine, or mycophenolate mofetil for shorter or longer periods of time [8]. More studies on the effects and side ef- fects of long term treatment of AD with systemic therapy are needed. AD poses a great burden both for patients and society and in recent decades the prevalence has increased substan- tially in many countries, notably in Western societies. Al- though some countries have witnessed a slight decrease in prevalence in very recent years the disease is continuingly on the rise, presently in many developing countries [9]. The causes for this increase in prevalence are not completely understood and as such there are still many unanswered questions regarding AD. Establishment of the Danish Atopy Database (DAD), a cohort with ongoing inclusion of outpatients with AD, al- lows the study of various aspects of the disease. Particularly, this cohort will provide the basis for studying the aetiology, natural history and management of AD. The database also provides possibility for long term follow-up of patients on systemic therapy. Herein we present our methodological considerations in regards to establishment of this cohort. METHODS Recruitment of Patients From January 1 st 2012 onwards all outpatients with AD referred to the Department of Dermatology, Bispebjerg Hos- pital, University of Copenhagen, Denmark will be included in the database. This department is a tertiary referral centre that manages around 500 patients with AD at the time. The yearly referral rate is around 150 new patients. Conse- quently, the database will allocate around 150 patients each year and will cover all ages of patients with AD; there are no formal exclusion criteria. However, in order to qualify for inclusion in the database, patients must fulfil the modified