Connections between psoriasis and Crohn's disease.
The prevalence of psoriasis in patients with Crohn's disease (CD) is higher than chance would allow if they were mutually exclusive diseases. A close examination reveals genetic and pathologic connections between these diseases. An appreciation for the role of tumor necrosis factor-alpha in both diseases has proven very important. Increased levels of this inflammatory cytokine have been measured in CD lesions, and in 1997 a clinical trial demonstrated the response of this disease to infliximab, a monoclonal antibody specific for tumor necrosis factor-alpha. A subsequent clinical trial evaluated infliximab in a patient with CD and psoriasis, another disease in which increased levels of tumor necrosis factor-alpha are seen in lesions. Scientists noticed the marked skin improvement of this patient and later demonstrated the efficacy of infliximab for psoriasis in a randomized, double-blind, placebo-controlled trial. Thus, an appreciation for connections between psoriasis and CD can suggest novel therapeutic strategies with ensuing benefits to patients. This article reviews epidemiologic, genetic, and pathologic connections between psoriasis and CD and discusses pharmaceuticals targeting inflammatory mediators common to each disease. (J Am Acad Dermatol 2003;48:805-21.)


OBJECTIVE
At the completion of this learning activity, participants should understand how psoriasis and Crohn's disease are related at epidemiologic, genetic, and pathological levels and should appreciate how to use this knowledge to treat these diseases.
Najarian
David James
DJ
University of Virginia School of Medicine, USA.
Gottlieb
Alice B
AB
D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D017209:Apoptosis / Q000502:physiology; D001402:B-Lymphocytes / Q000502:physiology; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics; D015897:Comorbidity; D003424:Crohn Disease / Q000188:drug therapy / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D006801:Humans; D000069285:Infliximab; D008264:Macrophages / Q000502:physiology; D009504:Neutrophils / Q000502:physiology; D011565:Psoriasis / Q000188:drug therapy / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D013601:T-Lymphocytes / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab