Sunday, February 3, 2013

Rare Forms of IBD

Crohn's and Ulcerative Colitis Aren't the Only Inflammatory Bowel Diseases



Crohn’s Disease and Ulcerative Colitis are the two best known types of inflammatory bowel disease (IBD) and get most of the attention, but there are other forms of IBD that are rarer but can be just as serious.  To give props to a few (not all) of the less common forms of IBD:

Ischemic Colitis.  The lack of bloodflow to the large intestine can cause inflammation, and in the extreme tissue death.  Ischemic colitis is generally acute, and can be brought on by everything from intense exercise to cocaine usage to vasoconstricting drugs.  Treatment is generally bowel rest and fluids, and most cases resolve on their own.  With extreme cases, tissue death occurs and requires immediate surgical intervention to prevent life threatening complications.

Ischemic Colitis can also become a chronic condition.  Similar to Crohn’s and UC, chronic ischemic colitis can case structuring and the associated complications.  Chronic ischemic colitis requires medical management and monitoring to prevent an acute emergency event. (1)

Behçet's disease.  Behçet's, first identified by Turkish dermatologist Hulusi Behçet, is a condition causing systemic vasculitis.  Behçet's is an autoimmune disease that primarily targets the mucus membranes, and oral lesions similar to those that appear with other forms of IBD are one of the more common symptoms.  While Behçet's can (and does) effect other systems not commonly impacted by other IBD diagnoses such as the genitals, lungs, and eyes. 

Behçet's overlaps with other forms of IBD in a second location – the ileocecal valve.  Behçet's can cause inflammation and damage to the valve area, which causes a mimicking of the symptoms of UC and Crohn’s.  Though Behçet's targets the blood vessels, it has shown to be responsive to treatment using the same anti TNF-alpha treatments that are used with other forms of IBD.  It is generally a diagnosis of exclusion – ruling out the more common forms of IBD and looking at extra-intestinal manifestations. (2)

Diversion Colitis.  Diversion colitis is an abnormal inflammation in a part of the colon that has been removed from function, generally by a colostomy or ileostomy.  While this can happen with surgical intervention to treat Crohn’s or UC, diversion colitis occurs in patients that have had surgical interventions not related to underlying IBD (e.g. from trauma or unrelated medical issues such as cancer).

Because it occurs following surgical intervention, diversion colitis is generally found through symptoms of abdominal pain or unusual rectal discharge.  Follow-up colonoscopy can also identify inflammation, polyps, granuloma formation, and other signs of IBD.  Diversion colitis is treated with enemas or systemic IBD drugs, or surgery to remove the effected portions. (3)

Collagenous and Lymphocitic Colitis (CLC).  CLC is a late onset disease, generally occurring in individuals that have not previously had IBD and manifest diarrheal symptoms in their 70s and 80s.  It is characterized by lymphocytes in the mucosal layer or inflammation of the collagenous areas.  The primary symptom, as noted, is uncontrolled diarrhea.  Though the origin is unknown, CLC is potentially another autoimmune disorder, and has some comorbidity with diseases like rheumatoid arthritis.

CLC is treated similar to other IBDs, with corticosteroids being the initial treatment option.  5-ASA treatments have been used, and anti TNF-alpha drugs may show potential promise. (4)

Unfortunately for those with rare diseases, the medical literature and treatment options tend to be more limited.  Drug companies are not eager to pursue additional indications for their drugs because the cost to do so will never be recouped for less common drugs, and doctors are not likely to see them (even busy GI doctors), so they are harder to diagnose.  That said, they are as damaging and as serious as the more common Crohn’s and UC versions of inflammatory bowel disease. 

Other autoimmune disorders are co-morbid with Crohn’s and Ulcerative Colitis, or may have intestinal manifestations not directly diagnosed as such (e.g. Lupus, Rheumatoid Arthritis, Sjogren's).  There are also even more rare IBD disorders, and there are other diseases that can mimic IBD symptoms such as irritable bowel syndrome, colon cancer, and celiac disease.  These disorders, and how they are differentially diagnosed from IBD, will be covered in future posts. 

Bottom Line


·         Crohn’s and Ulcerative Colitis are not the only forms of IBD out there, though they represent the lion’s share of diagnosed cases.
·         Less prevalent forms of IBD generally have similar treatments, but receive less press, fewer research dollars, and are less frequently seen (and understood) by doctors.

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1.       Sreenarasimhaiah, Jayaprakash.  Diagnosis and management of ischemic colitis.  Current Gastroenterology Reports, 2005.
2.       Lee, S. K., et al. Differential diagnosis of intestinal Behçet’s disease and Crohn’s disease by colonoscopic findings. Endoscopy, 2009.
3.       Ma, C. K., C. Gottlieb, and P. A. Haas. Diversion colitis: a clinicopathologic study of 21 cases. Human pathology.  1990.
4.       Zins, B. J., W. J. Sandborn, and W. J. Tremaine. Collagenous and lymphocytic colitis: subject review and therapeutic alternatives. The American journal of gastroenterology, 1995.


1 comment:

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