Crohn Disease - Gastrointestinal - Medbullets Step 2/3

Snapshot
A 16-year-old girl presents to her gastroenterologist with severe, crampy, abdominal pain and intermittent nonbloody diarrhea. She has also had unexpected weight loss over the past few months. She also reports having irritating sores in her mouth. On exam, she is noted to have aphthous sores on the bucca mucosal, and skin tags around the anus. A colonoscopy a week later shows cobblestone mucosa and non-contiguous involvement of the small intestine, suggesting a diagnosis of Crohn disease.
Introduction
Overview Crohn disease is an inflammatory bowel disease that can affect any part of the gastrointestinal (GI) tract, including the mouth and the anus characterized by abdominal pain and nonbloody diarrhea classically associated with non-contiguous involvement, or “skip lesions”, along GI tract Epidemiology demographics onset 15-30 or 60-70s years of age risk factors family history Pathogenesis mechanism chronic Th1-mediated inflammation starts as focal inflammatory infiltrates around crypts, evolves into transmural inflammation and noncaseating granulomas Prognosis unpredictable course of relapses and remissions
Presentation
Symptoms GI symptoms results from transmural involvement abdominal pain bloody or nonbloody diarrhea abscess fistulas strictures malnutrition extraintestinal manifestations arthralgias kidney stones calcium oxalate ankylosing spondylitis systemic symptoms chronic intermittent fever weight loss fatigue Physical exam skin and mucosal findings pyoderma gangrenosum erythema nodosum aphthous stomatitis perianal region skin tags scarring ocular finding episcleritis uveitis
Imaging
Abdominal radiograph indications assess for bowel obstruction CT of abdomen indications evaluation for obstruction, fistulas, or abscesses
Studies
Serum labs serology used when endoscopic studies and barium studies are inconclusive anti-Saccharomyces cerevisiae positive anti-neutrophil cytoplasmic antibody negative complete blood cell count elevated inflammatory markers Invasive studies colonoscopy or esophagogastroduodenoscopy indication diagnostic findings cobblestone mucosa transmural inflammation skip lesions bowel wall thickening ulcers fissures Histology noncaseating granulomas lymphoid aggregates
Differential
Ulcerative colitis key distinguishing factors bloody diarrhea disease affecting colon and always the rectum mucosal and submucosal inflammation only
Treatment
Medical 5-aminosalicylic acid agents indications mild disease initial therapy drugs mesalamine best initial therapy sulfasalazine corticosteroids indications for flares immunosuppressive agents drugs infliximab good for those with fistula formation azathioprine recurrent symptoms off steroids antibiotics drugs metronidazole/ciprofloxacin perianal involvement anti-diarrheal medications drugs loperamide replace fat soluble vitamins vitamin D can lead to hypocalcemia, hypophosphatemia, and secondary hyperparathyroidism Surgical surgical resection of affected area indications not curative
Complications
Fistula formation Colorectal cancer Abscesses Strictures