Chronic Inflammatory Bowel Disease

Objectives:

  1. Etiology-Pathogenesis
  2. Types (Crohn vs Ulcerative colitis)
  3. Morphology
  4. Clinical features
  5. Complications

 

Definition

Crohn Colitis and Ulcerative Colitis

Two inflammatory disorders of unknown cause affecting the GIT and share many common features.

  • Both Crohn disease and ulcerative colitis are chronic, relapsing inflammatory disorders of obscure origin.
  • Both exhibit extraintestinal inflammatory manifestations

Crohn disease:

is a granulomatous disease that may affect any portion of the GIT ( from esophagus to anus),but most often involves the small intestine and colon.

Ulcerative colitis:

is a nongranulomatous inflammatory disease limited to the colon.

 

Etiology

Pathogenesis
Unknown: Both diseases remain unexplained and are best designated as idiopathic.

Hypothesis:
1. Genetic
Twins-Families-close relatives
HLA-27 , HLA-DR2
2. Abnormal host immunreactivity(autoimmune disease)
3. Infectious causes (mycobacteria paratuberculosis)

Crohn’s Disease

Morphology

Crohn’s Disease
Location: Any part of GIT

  • Common:Terminal ilium (Regional enteritis)

Features:

  • Skip Lesions: wound or inflammation that is clearly patchy
  • Transmural chronic inflammation
  • Noncaseating granuloma

(type of nercosis)

  • Mucosal acute inflammation with deep fissuring
  • Fistula formation

abnormal connection between two hollow spaces

  • Marked fibrosis of the wall

Clinical Features

Crohn’s Disease
Variable

  • Diarrhea,fever,abdominal pain
  • Asymptomatic periods
  • Fecal blood leading to anemia
  • Severe lower abdominal pain;

Acute appendicitis
  • Intestinal obstruction
  • Fistulas (abnormal connection)
  • Protein loss
  • Vit b12 malabsorption

Complications

Crohn’s Disease
  • Intestinal obstruction due to fibrosis
  • Fistulas
  • Hypoproteinemia
  • Anemia (lack of vit B12 needed for RBC production)
  • Carcinoma(less risk than ulcerative colitis)
  • Extraintestinal manifestations

Ulcerative Colitis

Morphology

Ulcerative Colitis
Location:

  • Starts in the rectum and extends proximally to involves all colon

( pancolitis )

  • Small bowel not involved

Features:

  • Diffuse acute and chronic inflammation in the mucosa only (no transmural involvement)
  • Cryptitis and crypt abscess
  • Superficial mucosal ulcerations
  • No granulomas or fistulas

(main difference with Crohn’s Disease)

  • Goblet cell depletion
  • Mucosal regenerative hyperplasia forming pseudopolyps

(as seen in picture)

Clinical Features

Ulcerative Colitis
(Similarity to CD)

Variable (relapse and exacerbation)

  • Mucoid diarrhea (sometimes blood stained)
  • Massive bleeding (hemorrhage)
  • Obstruction due to toxic megacolon or cancer

Complications

Ulcerative Colitis
  • Anemia
  • Massive bleeding
  • Toxic megacolon (dilation)
  • Cancer
 Treatment:

  1. Medial (drugs)
  2. Surgical

Extraintestinal Manifestation

Ulcerative Colitis
Polyarthritis

is any type of arthritis that involves 5 or more joints simultaneously

Ankylosing spondylitis

is a type of arthritis that affects the spine.

Ankylosing spondylitis symptoms include pain and stiffness from the neck down to the lower back. The spine’s bones (vertebrae) fuse together, resulting in a rigid spine. These changes may be mild or severe, and may lead to a stooped-over posture

Erythema nodosum

s a type of skin inflammation that is located in a part of the fatty layer of skin. Erythema nodosum results in reddish, painful, tender lumps most commonly located in the front of the legs below the knees.

Primary sclerosing cholangitis

s a long-term progressive disease of the liver and gallbladder characterized by inflammation and scarring of the bile ducts which normally allow bile to drain from the gallbladder.

Uveitis
is inflammation of the uvea — the middle layer of the eye that consists of the iris, ciliary body and choroid. Uveitis can have many causes, including eye injury and inflammatory diseases.

 

 

Summary

Differences Crohn’s Disease Ulcerative Colitis
Location Any part of GIT Colon → Rectum
Inflammation Form Granulomas and Fistulas Do not form Granulomas and Fistulas
Depth Deep fissuring Superficial ulceration
Transmural Movement Yes

(defined as sectional interruption or loss of the five-layer structure)

 No
Similarities Chronic Inflammation