[Importance of epidemiologic surveillance in contact dermatitis: Spanish surveillance system on contact allergies]

The high prevalence of contact dermatitis means that this common medical problem has considerable personal, societal, and economic impact. Clinical and epidemiologic research is needed if we are to shed light on the real situation of contact dermatitis in Spain. In this article we will look at epidemiologic research from a practical point of view and analyze the role of the dermatologist in planning and designing studies. The advantages of multicenter studies are discussed, along with the roles of national and international surveillance networks. We present the Spanish Surveillance System on Contact Allergies, which serves as a bridge between Spanish dermatologists and the European Surveillance System on Contact Allergies. The present and future aims of the Spanish network are described.