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

Diagnosis

GI Symptoms

• Abdominal pain
• Diarrhea
• Wt 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

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

DDx

1. Ulcerative colitis
2. Ischemic bowel disease
3. Pseudomembranous enterocolitis
4. Lymphoma
5. Ileocecal amebiasis
6. Sarcoidosis
7. Yersinia
8. Campylobacter

Management

1. Rule-out complications:
   1. Obstruction
      1. Due to stricture or bowel wall edema
   2. Abscess
      1. Can be intraperitoneal, retroperitoneal, interloop, or intramesenteric
         1. More severe abdominal pain than usual
         2. Fever
         3. Hip or back pain and difficulty walking (retroperitoneal abscess)
   3. Fistula
      1. Occurs due to extension of intestinal fissure into adjacent structures
      2. Suspect if changes in pt's symptoms (e.g. BM frequency, amt of pain, wt loss)
   4. Perianal disease
      1. Abscess, fissures, fistulas, rectal prolapse
   5. Hemorrhage
      1. Erosion into a bowel wall vesel
   6. Toxic megacolon
      1. Can be associated w/ massive GI bleeding
2. Rule-out therapy complications:
   1. Leukopenia /thrombocytopenia
   2. Fever / infection
   3. Pancreatitis
   4. Renal / liver failure
3. Medications: Alterations should be discussed with GI
   1. Aminosalicylates (5-ASA) - Mild-to-moderate Crohn's dz. Give with probiotics.
      1. Sulfasalazine 3-5gm/day PO (sulfa drug)
         1. Caution: Can cause folate deficiency so give with folic acid, and can cause hemolytic anemia in G6PD pts
      2. Mesalamine 4gm/day PO
         1. Active moiety of sulfasalazine, and formed from prodrug balsalazide
      3. Balsalazide or Olsalazine - Bypasses small intestine to deliver drug into large intestine (better for UC)
   2. Anti-diarrheal - Use caution in pts with active inflammation as can precipitate toxic megacolon
      1. Loperamide 4-16mg/day
      2. Diphenoxylate 5-20mg/day
      3. Cholestyramine 4g once to six times daily
   3. Glucocorticoids - Symptomatic relief (course not altered)
      1. Prednisone - 40-60mg/day with taper once remission induced
      2. Methylprednisolone 20mg IV q6hr
      3. Hydrocortisone 100mg q8hr
         1. Do not start if any suspicion of infection (ie C.diff colitis)
         2. Double edge sword: Reduction of bone density in addition to underlying disease process(decreased Ca absorption)
   4. Antibiotics - Induce remission
      1. Ciprofloxacin 500mg q8-12hr OR
      2. Metronidazole 500mg q6hr OR
      3. Rifaximin 800mg BID
   5. Immunomodulators - Steroid-sparing agents used in fistulas and pts w/ surgical contraindication. Slower onset.
      1. 6-Mercaptopurine 1-1.5 mg/kg/day → Start at 50mg daily
      2. Azathioprine 2-2.5mg/kg/day → Start at 50mg daily
      3. Methotrexate IM
   6. Anti-TNF - Medically resistant moderate-to-severe Crohn's dz
      1. Infliximab (Remicade) 5mg/kg IV
      2. 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

See Also

• Ulcerative Colitis

Source

Tintinalli