Epidemiology

• Higher in White populations than in Black, Hispanic, or Asian populations
• Highest among individuals of Ashkenazi Jewish descent
• 15–35 years of age

Tip

Compared with Crohn disease, which is bimodal distribution with one peak at 15–35 years and another one at 55–70 years

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Etiology

• Genetic predisposition (e.g., HLA-B27 association)
• Ethnicity (White populations, individuals of Ashkenazi Jewish descent)
• Protective factors: smoking
  • The pathophysiology is not fully understood, as smoking has negative effects on other inflammatory diseases (e.g., Crohn disease).

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Pathophysiology

• Dysregulation of intestinal epithelium: increased permeability for luminal bacteria → activation of macrophages and dendritic cells → antigen presentation to macrophages and naive CD4+ cells
• Dysregulation of the immune system: upregulation of lymphatic cell activity (T cells, B cells, plasma cells) in bowel walls → enhanced immune reaction and cytotoxic effect on colonic epithelium → inflammation with local tissue damage (ulcerations, erosions, necrosis) in the submucosa and mucosa
  • Autoantibodies (pANCA) against cells of the intestinal epithelium
• Pattern of involvement
  • Ascending inflammation that begins in the rectum and spreads continuously proximally throughout the colon
  • Inflammation is limited to the mucosa and submucosa.

Crohn disease is characterized by transmural inflammation.

Unlike ulcerative colitis,

Tip

The rectum is always involved in ulcerative colitis.

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Clinical features

• Intestinal symptoms
  • Bloody diarrhea with mucus
  • Fecal urgency
  • Abdominal pain and cramps
  • Tenesmus
• Extraintestinal symptoms of ulcerative colitis
  • General: fatigue, fever
  • Skeletal (most common extraintestinal manifestation of ulcerative colitis): osteoarthritis, ankylosing spondylitis, sacroiliitis
  • Ocular: uveitis, episcleritis, iritis
  • Biliary: primary sclerosing cholangitis (it is rare for patients with ulcerative colitis to develop PSC, but up to 90% of all patients with PSC will also have ulcerative colitis)
  • Cutaneous
    • Erythema nodosum
    • Pyoderma gangrenosum
    • Aphthous stomatitis

Tip

PSC is often associated with inflammatory bowel disease, especially ulcerative colitis. However, only approximately 4% of patients with inflammatory bowel disease develop PSC.

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Diagnostics

Ileocolonoscopy

Recommended method for diagnosis and disease monitoring

Early stages

• Inflamed, erythematous, edematous mucosa
• Friable mucosa with bleeding on contact with endoscope A fibrin-covered ulceration (blue overlay) and several pseudopolyps (indicated by dashed lines) are visible.
• Fibrin-covered ulcers

Chronic disease

• Loss of haustra
• Pseudopolyps
  • Raised areas of normal mucosal tissue that result from repeated cycles of ulceration and healing
  • Ulceration → formation of granulation tissue → deposition of granulation tissue → epithelialization

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Treatment

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Complications

• ↑ Risk of cancer
  • chronic inflammation → hyperplasia → non-polypoid dysplasia → neoplasia
• Toxic megacolon
• Fulminant colitis
• Gastrointestinal bleeding (both acute and chronic)
• Perforation