Editing Crohn's disease (section)

== '''Presentation''' ==

* Classical presentation:
** Insidious onset
** Alternating symptomatic periods with abdominal pain and diarrhoea interspersed with asymptomatic periods. With time, the symptomatic periods become more severe, more frequent, and longer lasting
* Symptoms:
** Chronic diarrhoea - most common symptom
*** Stools rarely contain blood, mucus or pus (in contrast to UC)
*** Fewer daily bowel motions than UC
** Abdo pain - intermittent and colicky, commonly lower abdomen, and sometimes localised to RLQ
** Low-grade fever (~30%)
** Weight loss
** Loss of strength
** Malaise
* 1/3 have perianal involvement (fistulas, fissures, abscesses, skin tags)
** More aggressive disease if developing fistulas here
** Be concerned for Crohn's with large, thick skin tags ('elephant ear skin tags'), fissures off the midline, or complex fistulae
** Can initially present due to perianal disease as index finding
* Complications (see section below)
** Perforation/abscess
** Obstruction
** Bleeding
** Toxic megacolon
** Cancer

=== Extra-intestinal manifestations of IBD common (up to half) ===

** Higher prevalence in CD than UC
** Same complications for UC and CD

{| class="wikitable"
|Dermatologic
|Erythema nodosum (10%)


Red painful swollen nodules

Usually respond to systemic steroids
|Likely to improve after resection of intestinal disease
|-
|
|Pyoderma gangrenosum (1-12%)


Extremely painful ulcerating lesions that typically occur at sites of repeated trauma/surgery/stomas. Key process is neutrophilic dermatosis. 


Associated with IBD, RA, leukaemia.


Avoid debridement.

Intralesional steroid injections (triamcinalone), topical steroids or tacrolimus 0.1%, or systemic biologic therapy
|Likely to improve after resection of intestinal disease
|-
|
|Aphthous stomatitis
|Useful to differentiate between Crohn's and UC
|-
|Rheumatologic
|Peripheral arthritis (5-20%)


Commonly involving knees or MCPJ
|
|-
|
|Spondylitis (1-26%)


Particularly men with IBD

Inflammatory back pain, especially in lower back or buttocks, in the morning or after rest, which is often relieved by exercise.
|Unlikely to improve after resection of intestinal disease
|-
|
|Symmetric sacro-ileitis (<10%)
|
|-
|
|Amyloidosis
|
|-
|Ocular (0.3-5%)
|Conjunctivitis
|
|-
|
|Uveitis


Topical or systemic glucocorticoids
|
|-
|
|Iritis episcleritis


|
|-
|HPB
|PSC (2-5%)
|Unlikely to improve after resection of intestinal disease

Higher risk of developing pouchitis
|-
|
|Autoimmune hepatitis
|
|-
|
|Hepatic steatosis
|
|-
|
|Cholelithiasis
|
|-
|
|Pancreatitis
|
|-
|Renal
|Nephrolithiasis (6-23%)
|
|-
|
|Obstructive uropathy
|
|-
|
|Nephrotic syndrome
|
|-
|Cardiovascular
|Hypercoagulable state
|DVT, PE, CVA
|-
|
|Endocarditis
|
|-
|
|Myocarditis
|
|-
|
|Pleuropericarditis
|
|-
|Bone
|Osteoporosis
|
|-
|
|Osteomalacia
|
|}