Metastatic Crohn disease: a review of dermatologic manifestations and treatment.

It is estimated that almost half of patients affected with Crohn disease (CD) experience a dermatologic manifestation of the condition. Metastatic CD (MCD) is a rare dermatologic entity, with as few as 100 cases reported in the literature. As such, MCD presents a clinical dilemma in diagnosis and management. The etiology of MCD is not well defined; however, prevailing theories agree that the underlying mechanism is an immunologic response to gut antigens. Diagnosis requires a high index of suspicion and usually is made by exclusion of other processes. Treatment success has been reported with the use of antibiotics, immunosuppressants, and sometimes surgical treatment. We review the etiology/epidemiology, diagnostic criteria, and treatment of this uncommon condition.