Ulcerative Colitis
(Am J Gastroenterol. 2004;99:1371-1385.; Gastroenterology. 2004;126:1582-1592.; N Engl J Med. 2002; 347:417-429)
DEFINITION:
Idiopathic inflammation of the colonic mucosa (as opposed to Crohn’s which is transmural and any segment of the GI tract)
Backwash Ileitis: Unusual cases of ulcerative colitis involving the terminal ileum
Endoscopic/Radiologic appearance same as UC; If deeper linear ulcers/strictures seen in ileum, Crohn’s Disease is most likely diagnosis
Intermediate Colitis:
In 5-10% of patients with chronic colitis a clear distinction between UC and CD cannot be made even with mucosal biopsy
Many Crohn’s Disease cases diagnosed after ‘curative surgery for UC’; Recurrent ileitis of ileostomy or ileoanal pouch leads to diagnosis of Crohn’s
Cuffitis and Pouchitis: See end of this section
DDX:
Infectious: bacterial (E. coli, Salmonella, Shigella, Yersinia, Campylobacter, Mycobacterium, C. difficile), amebic, CMV/HSV, STDs
Ischemic colitis, Diverticulitis, Colorectal cancer
Intestinal lymphoma, Collagenous/Lymphocytic colitis (Microscopic colitis), Celiac sprue, Radiation enteropathy
IBS, Appendicitis, Solitary rectal ulcer syndrome
EPIDEMIOLOGY:
Prevalence 1:1000 (high because often presents in younger population initially); ♂ = ♀
Bimodal with peaks in 20’s and 50-70’s; ↑ incidence in Caucasians, Jews, and non-smokers
Appendicitis prior to age 20 and tobacco use have been reported to be protective against the development of UC
Prophylactic appendectomy for a normal appendix has no protective value
ETIOLOGIES:
The cause is unknown
Greatest risk is positive family history (10-15% have a family history); Genetic link has not been identified
Less familial association than Crohn’s
Three genetic syndromes associated: Turner’s , Glycogen storage disease 1B, Hermansky-Pudlak (albinism, platelet defect)
PATHOPHYSIOLOGY:
Extent: Involves rectum (95%) and extends proximally and contiguously
Distribution: 50% proctosigmoiditis, 30% left-sided colitis, and 20% extensive colitis
Appearance: granular, friable mucosa with diffuse ulceration confined to only colon (not small bowel)
Microscopy: superficial microulcerations; crypt abscesses (PMNs); goblet cell depletion; basal plasmacytosis
CLINICAL MANIFESTATIONS/PHYSICAL EXAM:
Rectal disease with grossly bloody diarrhea, left lower abdominal cramps with tenesmus and urgency; Perianal disease is rare
Fulminant colitis:
Megacolon (6-13% of patients): colon dilation (Transverse ≥6 cm on KUB), colonic atony, and systemic toxicity
Toxic Megacolon (2 or more): HR >100/min, Temp >101.5°F (38.6°C), WBC >10,000, Hypoalbuminemia <3.0 gm/dl
Perforation: pneumoperitoneum, peritonitis
Extracolonic (25%): most mimic disease activity:
Seronegative (RF−) arthritis is most common, 25% of patients: large joint, unilateral, non-deforming (coincides with colitis activity)
Ankylosing spondylitis 30-fold increase: 50% are HLA-B27 positive (doesn’t coincide with colitis activity)
Osteopenia/Osteoporosis: risks: steroid use, malabsorbed Ca/D, ↓ BMI, tobacco; generally treated like any other patient (i.e. Bisphosphonates)
Derm:
Erythema nodosum: painful pretibial erythematous subcutaneous nodules (coincides with colitis activity)
Pyoderma gangrenosum: pustular lesions that ulcerate and exhibit pathergy (doesn’t coincide with colitis activity)
Ocular: anterior uveitis (iritis), episcleritis (if HLA-B27 + doesn’t coincide with colitis activity; If HLA-B27 −, it does coincide with colitis activity)Related posts:
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