Disease-related and drug-induced skin manifestations in inflammatory bowel disease

Skin manifestations are common in patients with inflammatory bowel diseases (IBD) and can be part of a concomitant illness with a shared genetic background, an extra-intestinal manifestation of the disease, or a drug side-effect. Areas covered: We provide a practical overview of the epidemiology, pathogenesis, diagnosis, therapeutic approach and prognosis of the most frequent disease-related and drug-induced cutaneous manifestations in IBD, illustrated by cases encountered in our clinical practice. Among the most frequently encountered IBD-related lesions are erythema nodosum, pyoderma gangrenosum and Sweet's syndrome. Common skin manifestations with a strong association to TNF antagonists are local injection site reactions, psoriasiform lesions, cutaneous infections, vasculitides and lupus-like syndromes. In addition, we discuss the relation of thiopurines and TNF antagonists with the risk of skin cancer. Expert commentary: We hope this review will help caretakers involved in the management of IBD patients to recognize the lesions and to manage them in close collaboration with a dedicated dermatologist.