Skin diseases and inflammatory bowel disease. Part II. Nosological parallels, diagnostic problems and adverse effects of treatment: Fields for collaboration between gastroenterologists and dermatologists

In nosological terms, there is a striking pathophysiological resemblance between certain subgroups of skin and gastrointestinal diseases, probably as a result of the overall structural similarity of the two systems. Despite the fact that the term "idiopathic inflammatory disease of the skin" is neither formal nor widely used in current medical literature, it could be applied as an umbrella designation for a group of dermatic disorders with disease characteristics similar to those which define the idiopathic inflammatory bowel diseases (IBD). Interdisciplinary research on these similarities may prove a particularly fruitful field of cooperation for gastroenterologists and dermatologists. In addition, certain skin disorders can mimic symptoms of IBD, such as herpes zoster of the lower thoracic cavity and the abdominal area, which presents with abdominal pain. Awareness of skin conditions masquerading as an IBD relapse is mandatory to the gastroenterologist who monitors patients with established IBD. Appropriate recognition and prevention of potential dermatic side effects of treatment for IBD, and early identification of gastroenterological side effects of treatment given for dermatological disorders in patients with IBD are of capital importance for their optimal care. The possible sequelae of cosmetic preparations in patients with IBD are an emerging medical field with many questions still to be addressed and clarified. All these issues may benefit from collaboration between dermatologists and gastroenterologists. In this review these relevant issues are summarized in the hope of contributing to the continuing promising scientific dialogue between gastroenterologists and dermatologists in the interrelated fields of the "idiopathic inflammatory bowel" and skin disorders.