First AD

Second AD

A 28-year-old man with Crohn colitis on maintenance therapy with infliximab 5 mg/kg every 8 weeks presents with perianal pain. On examination, he has a 1-cm tender lesion with fluctuance near the anus. 

D. Perform exam under anesthesia in conjunction with MRI of pelvis

Answer: D. Perform exam under anesthesia in conjunction with MRI of pelvis

The main differential diagnosis in this patient is abscess and fistula. Before treatment is initiated, further evaluation with a comprehensive exam and an imaging study (such as MRI) is warranted. Incision and drainage followed by antibiotics is appropriate for superficial abscesses. If a fistula is discovered on imaging, management may also include addition of a non-cutting seton or fistulotomy in addition to antibiotics.

Image of severe colitis courtesy of David Schwartz, MD.

Gastrointestinal Disorders

What would your diagnosis be in this young man and how would that inform your next step? 

Perianal Pain Associated With Crohn Colitis: What Next?