Crohn's disease

Background

• Can involve any part of the GI tract from the mouth to the anus
• Bimodal distribution: 15-22yr, 55-60yr
• Pathology
  • All layers of the bowel are involved
    • Reason why fistulas and abscesses are common complications
  • "Skip lesions" are common

Clinical Features

GI Symptoms

• Abdominal pain
• Diarrhea
• Weight loss
• Perianal fissures or fistulas

Extraintestinal Symptoms (50%)

• Arthritis
  • Peripheral arthritis
    • Migratory monarticular or polyarticular
  • Ankylosing spondylitis
    • Pain/stiffness of spine, hips, neck, rib cage
  • Sacroiliitis
  • Low back pain w/ morning stiffness
• Ocular
  • Uveitis
    • Acute blurring of vision, photophobia, pain, perilimbic scleral injection
  • Episcleritis
    • Eye burning or itching w/o visual changes or pain; scleral and conj hyperemia
• Dermatologic
  • Erythema nodosum
    • Painful, red, raised nodules on extensor surfaces of arms/legs
  • Pyoderma gangrenosum
    • Violacious, ulcerative lesions w/ necrotic center found in pretibial region or trunk
• Hepatobiliary
  • Cholelithiasis (33%)
  • Fatty liver
  • Autoimmune hepatitis
  • Primary sclerosing cholangitis
  • Cholangiocarcinoma
• Vascular
  • Thromboembolic disease

Differential Diagnosis

• Ulcerative colitis
• Ischemic bowel disease
• Pseudomembranous enterocolitis
• Lymphoma
• Ileocecal amebiasis
• Sarcoidosis
• Yersinia
• Campylobacter

Diagnosis

Work-Up

• Labs
  • CBC
  • Chemistry
  • ESR/CRP
  • C.diff toxin
  • Type and Cross/Screen if any bleeding suspicion
• Imaging:
  • Plain abdominal films - r/o obstruction, perforation and toxic megacolon
  • CT A/P
    • Most useful diagnostic test in pts w/ acute symptoms who have known or suspected Crohn
    • Findings: bowel wall thickening, mesenteric edema, local abscess, fistulas

Management

Initial ED Management: IVF, bowel rest, analgesia, electrolyte correction, and NGT (if obstruction/ileus/toxic megacolon)

• Medications: Alterations should be discussed with GI
  • Aminosalicylates (5-ASA) - Mild-to-moderate Crohn's dz. Give with probiotics.
    • Sulfasalazine 3-5gm/day PO (sulfa drug)
      • Caution: Can cause folate deficiency so give with folic acid, and can cause hemolytic anemia in G6PD pts
    • Mesalamine 4gm/day PO
      • Active moiety of sulfasalazine, and formed from prodrug balsalazide
    • Balsalazide or Olsalazine - Bypasses small intestine to deliver drug into large intestine (better for UC)
  • Anti-diarrheal - Use caution in pts with active inflammation as can precipitate toxic megacolon
    • Loperamide 4-16mg/day
    • Diphenoxylate 5-20mg/day
    • Cholestyramine 4g once to six times daily
  • Glucocorticoids - Symptomatic relief (course not altered)
    • Prednisone - 40-60mg/day with taper once remission induced
    • Methylprednisolone 20mg IV q6hr
    • Hydrocortisone 100mg q8hr
      • Do not start if any suspicion of infection (ie C.diff colitis)
      • Double edge sword: Reduction of bone density in addition to underlying disease process(decreased Ca absorption)
  • Antibiotics - Induce remission
    • Ciprofloxacin 500mg q8-12hr OR
    • Metronidazole 500mg q6hr OR
    • Rifaximin 800mg BID
  • Immunomodulators - Steroid-sparing agents used in fistulas and pts w/ surgical contraindication. Slower onset.
    • 6-Mercaptopurine 1-1.5 mg/kg/day → Start at 50mg daily
    • Azathioprine 2-2.5mg/kg/day → Start at 50mg daily
    • Methotrexate IM
  • Anti-TNF - Medically resistant moderate-to-severe Crohn's dz
    • Infliximab (Remicade) 5mg/kg IV
    • Adalimumab (Humira), Natalizumab or certolizumab pegol can also be used

Disposition

Inpatient Admission

• Metabolic derangements (ie electrolyte imbalance or severe dehydration)
• Fulminate colitis
• Obstruction
• Peritonitis
• Significant hemorrhage

Surgical Intervention

Consult EARLY if any of the following suspicions

• Perforation
• Abscess/fistula formation
• Toxic megacolon
• Significant hemorrhage
• Perianal disease
• Failed medical management

Complications

• Obstruction
  • Due to stricture or bowel wall edema
• Abscess
  • Can be intraperitoneal, retroperitoneal, interloop, or intramesenteric
    • More severe abdominal pain than usual
    • Fever
    • Hip or back pain and difficulty walking (retroperitoneal abscess)
• Fistula
  • Occurs due to extension of intestinal fissure into adjacent structures
  • Suspect if changes in pt's symptoms (e.g. BM frequency, amt of pain, wt loss)
• Perianal disease
  • Abscess, fissures, fistulas, rectal prolapse
• Hemorrhage
  • Erosion into a bowel wall vesel
• Toxic megacolon
  • Can be associated w/ massive GI bleeding

Therapy complications

• Leukopenia /thrombocytopenia
• Fever / infection
• Pancreatitis
• Renal / liver failure

See Also

• Ulcerative Colitis
• Colitis