Metastatic Crohn's disease: a case report.
Metastatic Crohn's disease (MCD) is a rare extraintestinal manifestation of Crohn's disease characterized by the histologic finding of granulomatous dermatitis at a site noncontiguous to the gastrointestinal tract. An adolescent had MCD of the face that was initially mistaken for severe, treatment-resistant acne. Histopathologic and microbiologic evaluation, combined with clinical examination and response to therapy, ultimately led to the correct diagnosis. Mycobacterium paratuberculosis is a suspected cause of Crohn's disease. Polymerase chain reaction was used to detect genomic DNA specific for the organism in biopsy specimens from the patient's cutaneous lesions. This study failed to demonstrate M. paratuberculosis in the specimens.