Crohn’s disease named after Burrill Bernard Crohn, an American gastroenterologist also called regional enteritis is a chronic, episodic inflammatory bowel disease (IBD) affecting any part of the digestive tract from mouth to anus with varying symptoms between affected individuals. It is characterized by transmural inflammation and skip lesions (i. e. , inflammation with areas of normal lining in between) with symptoms of abdominal pain, diarrhea (possibly bloody) and weight loss.
Complications outside the alimentary canal include skin rashes, arthritis and eye inflammation [Wikipedia, the free encyclopedia 2007]. Statistically Crohn’s disease affects 400,000 to 600,000 people in North America and about 27 to 48 people per 100,000 in Northern Europe. Generally, the disease develops in individuals in their teenage years although people in 60s and 70s are also at increased risk.
Risks of the disease being passed on to siblings and spouse are very strong affecting both males and females, meaning the susceptibility of genetic component and environmental factor requires to be considered [Wikipedia, the free encyclopedia 2007]. The exact cause of Crohn’s disease is not known but is believed to be an autoimmune disease with the immune system contributing to the damage of digestive tract due to inflammation. Most of the cytokines in the Th1 classification such as TNF-? , interleukin-2 and interferon ? are active in causing inflammation [Wikipedia, the free encyclopedia 2007].
Crohn’s disease is not curable with any of the known medical or surgical methods and the medical treatments used are only to keep the disease in remission by giving steroid medications, immunomodulators like azathioprine and methotrexate and newer biological medications such as infliximab [Wikipedia, the free encyclopedia 2007]. Types of Crohn’s Disease Crohn’s disease is of five types based on the gastrointestinal area affected. The lesions due to Crohn’s disease may appear in any part of the alimentary canal from mouth to anus.
Gastroduodenal Crohn’s Disease: The Crohn’s disease affecting stomach and duodenum or the starting portion of the small intestine is called gastroduodenal Crohn’s disease. Often correct diagnoses of the disease are not made until all the options to treat ulcer fail or the disease identified far down the gastrointestinal tract. Symptoms of this type of disease consist of loss of weight and appetite, nausea, pain in the upper middle part of the abdomen and vomiting. Vomiting indicates the obstruction of narrowed segments of the bowel (CCFA). Jejunoileitis:
Crohn’s disease affecting the longest portion of small intestine (jejunum) between duodenum and ileum is called jejunoileitis. Mild to intense abdominal pain and cramps after meals, diarrhea, malnutrition caused by malabsorption of nutrients and Fistulas are some of the symptoms of this type. The diseased portion of small intestine may be linked to another area of the intestine or another organ, such as the bladder and it is important t note that the risk of developing infections outside the digestive tract is high due to fistulas. Jejunoileitis may produce patchy areas of inflammation in the jejunum (CCFA). Ileitis:
Crohn’s disease affecting the lowest or last part of the small intestine (i. e. , ileum) is called ileitis. Diarrhea, cramping or pain in the right lower quadrant and periumbilical area after meals, malabsorption of vitamin B12 leading to tingling of fingers or toes and folate deficiency hindering the development of RBC making the patient anemic are some of the symptoms of Crohn’s disease of ileum. Complications may lead to fistulas or inflammatory abscess in right lower quadrant of abdomen (CCFA). Illeocolitis: It is one of the commonest Crohn’s disease affecting the lowest part of small intestine (ileum) and the large intestine (colon).
Generally, the affected portion of the colon is continuous with the diseased portion of ileum involving the ileocecal valve between the ileum and the colon. In some cases, discontinuous inflammation in colon with ileum may be observed. Symptoms are essentially the same as in ileitis with loss of weight. Crohn’s Colitis (Granulomatous Colitis): Crohn’s disease affecting the colon is called Crohn’s colitis or Granulomatous Colitis. It differs from ulcerative colitis in two ways: 1. Ulcerative colitis is always continuous whereas in Crohn’s colitis areas of healthy tissue are interspersed between areas of diseased tissue.
2. Ulcerative colitis always affects the rectum and areas of colon beyond rectum, whereas Crohn’s colitis appears only in the colon. Diarrhea, rectal bleeding and disease around the anus (such as abscess, fistulas and ulcers) are the symptoms of this type. Skin lesions and joint pains are common in this type (CCFA). Causes & Risk Factors Crohn’s disease is described as an “idiopathic” disease since the causes of disease are not yet identified. Inflammation is a part of body’s immune response system caused due to a “trigger. ” However, no trigger has been identified to date to cause a trigger causing inflammation.
Genetically Crohn’s disease is said to have a complex linkage, since about 20-25% of patients have their relatives suffering from Crohn’s disease or Ulcerative colitis. Thus, physicians classify Crohn’s disease as a “familial” or “complex” genetic disease i. e. , the offspring will not copy the defective gene from each of the parent like in a “simple” genetic disease. Genetic mutations in a gene called NOD2/CARD15 is found in people suffering from Crohn’s disease and is believed to associated with early onset of symptoms and cause relapse after surgery (Mayo clinic).
Maycobacterium avium paratuberculosis (MAP), a bacterium causing intestinal disease in cattle is believed to be involved in development of Crohn’s disease (Mayo clinic). Immunological evidence suggests that those suffering from IBD loose tolerance for bacteria resulting in destruction of TH2 cells, which are responsible for deactivation of the immune system to respond after an invasion by microorganisms leading to overreaction and consequently pain, fever and even tissue damage. Certain environmental factors are also believed to have an impact on initial episodes or relapses.
Crohn’s disease primarily affects the people living in Western industrialized societies. Risk of developing Crohn’s disease is high in people with age group of 15-35 years with Jewish ancestry or European descent and smoking habits (Mayo Clinic) Signs & Symptoms Symptoms of the disease are “persistent recurrent diarrhea” often with frequent loose or watery bowel movements; the stool is seldom accompanied with thick, dark blood. Patients may suffer from crampy, achy, sharp abdominal pain in the lower right side of the abdomen below the bellybutton since most of the Crohn’s disease occurs in the terminal ileum.
Some patients develop high fever followed by fatigue during acute flare up of the disease (ehealthmd). In addition to the above loss of appetite, loss of weight, delayed growth and sexual development are also observed in some patients. Development of fissures in the anal lining causing pain and bleeding, fistulas may open into bladder or vagina with drainage of mucus, pus or stool from these openings (CCFA). According to ehealthmd signs and symptoms not related to digestive tract are: • Inflammation an reddening of eyes (iritis)
• Pain in the joints especially those of large joints such as knees, ankles, elbows, wrists and shoulders. • Lesions on skin including red nodules on the shins or calves i. e. , Erythema nodosum. • Sores in the mouth i. e. , Aphthous ulcers. In addition to the above eyes are affected due to uveitis, liver (PSC), skin is affected due to pyoderma gangrenosum and kidney is affected due to kidney stones (healthscout). Medical Tests & Diagnosis Methods/Tools The diagnostic tests for Crohn’s disease include: I. Imaging tests II. Laboratory tests Imaging tests include the following:
Sigmoidoscopy: In this procedure, the doctor directly examines the lower portion of the colon and rectal lining with the help of a 60-centimeter flexible fiber optic scope containing a light source and a camera lens by inserting into the anus and pushing it into the rectum further into the descending sigmoid colon checking for irregularities if any. The procedure of Sigmoidoscopy is generally used diagnosing ulcerative colitis and rule out Crohn’s disease. Colonoscopy: This procedure permits the doctor to examine the colon in its entirety i. e.
, from the rectum to the terminal ileum, the end of the small intestine. Current colonoscopes make use a microchip-driven electronic imaging and screen projection. The procedure is performed with patient under “Conscious Anesthesia” in a hospital or endoscopy clinic. Small tissue samples are collected for biopsy to check for precancerous condition with the help of a small set of forceps inside the colonoscope. Barium Enema: Barium sulfate suspension is injected into the colon through a tube inserted into the rectum and number of x-rays taken.
The “dye” helps in giving a clear view of the soft tissue of the bowel. The barium enema clearly indicates the continuity of diseased portion to a radiologist and a gastroenterologist. According to Mayoclinic. com ERCP (Endoscopic retrograde cholangiopancreatography): In this procedure, the doctor examines bile ducts in the liver and pancreatic duct. Endoscopic Ultrasound: In this procedure, an ultrasound probe attached to an endoscope is used to get images of the gut below the surface. The procedure is used to diagnose perianal fistulas due to Crohn’s disease.
Capsule Endoscopy: In this procedure, the patient is required to swallow a capsule with a camera inside to provide images of sections of small intestines which are beyond the reach of a an EGD Computerized Tomography (CT): This procedure helps to view the entire bowel along with tissues outside the bowel not visible with any other diagnostic procedures. This procedure may be recommended to understand the exact location of diseased portion and the extent of disease along with complications such as partial blockages, abscesses or fistulas.
Laboratory tests help confirm Crohn’s disease. Increase in White Blood Cell (WBC) count and Erythrocyte Sedimentation Rate (ESR) indicate the presence of a inflammatory disease. Low Red Blood Corpuscles (RBC) count is an indication of anemia due to malabsorption of iron, excessive internal bleeding or chronic illness. The presence of C-reactive protein also indicates intestinal inflammation (Mayoclinic). Treatment Options Medical management of the disease consists of “reducing the symptoms and bringing on remission. ” Following medications are used to treat Crohn’s disease:
? 5-ASA compounds: Most of the medications for Crohn’s disease and ulcerative colitis have 5-aminosalicylic acid that inhibits substances causing inflammation in the immune system, “sulfa drugs” also called sulfasalazine and trade named as Azulfadine is one such drug. It is important to note that sulfasalazine has many side affects such as headaches, nausea and vomiting. Drugs with following trade names and formulations are available in market: ? Asacol (mesalamine), available as a 400-milligram coated caplet ? Pentasa (mesalamine), available as a 250-milligram capsule
? Rowasa (mesalamine), available as a 500-milligram rectal suppository or a 4,000 milligram enema (effective for Crohn’s colitis, which affects the rectum and left side of the colon) ? Dipentum (osalazine), available as a 250-milligram capsule ? Steroids are potentially toxic, power drugs used to alleviate inflammation and to suppress immune system of the body. Some of the commonly used steroids used to treat Crohn’s disease and ulcerative colitis include Prednisone and prednisolone. But these have dangerous side effects.
? Medications that suppress the immune system: Immunosuppressive drugs are generally used in in conjunction with organ transplants to minimize the possibility of rejection. ? Antibiotics: Broad spectrum antibiotics like Ciprofloxacin (Cipro), Clarithromycin (Biaxin) and Ampicillin are used to treat Crohn’s disease. ? Infliximab: This drug is a “chimeric monoclonal antibody-a manufactured protein” trade named as Remicade is used to treat specific biological substance. Prevention Methods Crohn’s disease cannot be prevented since the causes are unknown. Bibliography 1.
Crohn’s Disease (2007), [Online], Page retrieved on March 08,2007 from: http://en. wikipedia. org/wiki/Crohn’s_disease 2. Types Of Crohn’s Disease (2004). ehealthMD. Page retrieved on March 08, 2007 from: http://www. ehealthmd. com/library/crohnsdisease/CD_types. html 3. About Crohn’s Disease (2007). Crohn’s & Colitis Foundation of America (CCFA). Page retrieved on March 08, 2007 from: http://www. ccfa. org/info/about/crohns 4. What Causes Crohn’s Disease? (2004). ehealthMD. Page retrieved on March 08, 2007 from: http://www. ehealthmd. com/library/crohnsdisease/CD_causes. html 5.
What Are The Symptoms Of Crohn’s Disease? (2004). ehealthMD. Page retrieved on March 08, 2007 from: http://www. ehealthmd. com/library/crohnsdisease/CD_symptoms. html 6. Crohn’s Disease (2001). USA Today. Page retrieved on March 08, 2007 from: http://www. healthscout. com/ency/68/223/main. html 7. Crohn’s Disease Causes (2006). MayoClinic. com. Page retrieved on March 08, 2007 from: http://www. mayoclinic. com/health/crohns-disease/DS00104/DSECTION=3 8. Crohn’s Disease Risk Factors (2006). MayoClinic. com. Page retrieved on March 08, 2007 from: http://www. mayoclinic. com/health/crohns-disease/DS00104/DSECTION=4