Disseminated Mycobacterial Infection With Reactive Polyarthritis (Poncet's Disease) During Immune-suppressive Treatment Including Ustekinumab for Pediatric Crohn's Disease.

Children with inflammatory bowel disease receiving combination immunosuppressive treatments including tumor necrosis factor alpha inhibitors and anti-IL-12/23 agents are at higher risk for MI. Disseminated MI should be considered and ruled out in these patients when presenting with pulmonary, extrapulmonary or unusual clinical manifestations, like PD. The collection of multiple specimens (including intestinal biopsies) for mycobacterial culture is recommended when mycobacterial disease is suspected.