Crohn's disease

Crohn's disease
Crohn's disease (also spelled Crohn disease) is a chronic inflammatory disease of the intestines. It primarily causes ulcerations (breaks in the lining) of the small and large intestines, but can affect the digestive system anywhere from the mouth to the anus. It is named after the physician who described the disease in 1932. It also is called granulomatous enteritis or colitis, regional enteritis, ileitis, or terminal ileitis.
Crohn's disease is related closely to another chronic inflammatory condition that involves only the colon called ulcerative colitis. Together, Crohn's disease and ulcerative colitis are frequently referred to as inflammatory bowel disease (IBD). Ulcerative colitis and Crohn's disease have no medical cure. Once the diseases begin, they tend to fluctuate between periods of inactivity (remission) and activity (relapse).
Inflammatory bowel disease affects approximately 500,000 to two million people in the United States. Men and women are affected equally. Americans of Jewish European descent are 4 to 5 times more likely to develop IBD than the general population. IBD has historically been considered predominately disease of Caucasians, but there has been an increase in reported cases in African Americans suffering from IBD. The prevalence appears to be lower among Hispanic and Asian populations. IBD most commonly begins during adolescence and early adulthood (usually between the ages of 15 and 35). There is a small second peak of newly-diagnosed cases after age 50. The number of new cases (incidence) and number of cases (prevalence) of Crohn's disease in the United States are rising, although the reason for this is not completely understood.
Crohn's disease tends to be more common in relatives of patients with Crohn's disease. If a person has a relative with the disease, his/her risk of developing the disease is estimated to be at least 10 times that of the general population and 30 times greater if the relative with Crohn's disease is a sibling. It also is more common among relatives of patients with ulcerative colitis.

 Symptoms 
Common symptoms of Crohn's disease include abdominal pain, diarrhea, and weight loss. Less common symptoms include poor appetite, fever, night sweats, rectal pain, and occasionally rectal bleeding. The symptoms of Crohn's disease are dependent on the location, the extent, and the severity of the inflammation. The different subtypes of Crohn's disease and their symptoms are:
1. Crohn's colitis is inflammation that is confined to the colon. Abdominal pain and bloody diarrhea are the common symptoms. Anal fistulae and peri-rectal abscesses also can occur.
2. Crohn's enteritis refers to inflammation confined to the small intestine (the first part, called the jejunum or the second part, called the ileum). Involvement of the ileum alone is referred to as Crohn's ileitis. Abdominal pain and diarrhea are the common symptoms. Obstruction of the small intestine also can occur.
3. Crohn's terminal ileitis is inflammation that affects only the very end of the small intestine (terminal ileum), the part of the small intestine closest to the colon. Abdominal pain and diarrhea are the common symptoms. Small intestinal obstruction also can occur.
4. Crohn's entero-colitis and ileo-colitis are terms to describe inflammation that involve both the small intestine and the colon. Bloody diarrhea and abdominal pain are the common symptoms. Small intestinal obstruction also can occur.
Crohn's terminal ileitis and ileo-colitis are the most common types of Crohn's disease. (Ulcerative colitis frequently involves only the rectum or rectum and sigmoid colon at the distal end of the colon. These are called ulcerative proctitis and procto-sigmoiditis, respectively.)
Up to one-third of patients with Crohn's disease may have one or more of the following conditions involving the anal area:
1. Swelling of the tissue of the anal sphincter, the muscle at the end of the colon that controls defecation.
2. Development of ulcers and fissures (long ulcers) within the anal sphincter. These ulcers and fissures can cause bleeding and pain with defecation.
3. Development of anal fistulae (abnormal tunnels) between the anus or rectum and the skin surrounding the anus). Mucous and pus may drain from the openings of the fistulae on the skin.

4. Development of peri-rectal abscesses (collections of pus in the anal and rectal area). Peri-rectal abscesses can cause fever, pain and tenderness around the anus.
 Treatment
The symptoms and severity of Crohn's disease vary among patients. Patients with mild or no symptoms may not need treatment. Patients whose disease is in remission (where symptoms are absent) also may not need treatment.
Crohn's disease medications
There is no medication that can cure Crohn's disease. Patients with Crohn's disease typically will experience periods of relapse (worsening of inflammation) followed by periods of remission (lessening of inflammation) lasting months to years. During relapses, symptoms of abdominal pain, diarrhea, and rectal bleeding worsen. During remissions, these symptoms improve. Remissions usually occur because of treatment with medications or surgery, but occasionally they occur spontaneously without any treatment.
Since there is no cure for Crohn's disease, the goals of treatment are to 1) induce remissions, 2) maintain remissions, 3) minimize side effects of treatment, and 4) improve the quality of life. Treatment of Crohn's disease and ulcerative colitis with medications is similar though not always identical.
Medications for treating Crohn's disease include
1. anti-inflammatory agents such as 5-ASA compounds and corticosteroids,
2. topical antibiotics, and
3. immuno-modulators.
Selection of treatment regimens depends on disease severity, disease location, and disease-associated complications. Various guidelines recommend that approaches be sequential - initially to induce clinical remission, and then to maintain remissions. Initial evidence of improvement should be seen within 2 to 4 weeks and maximal improvement should be seen in 12 to 16 weeks3. The classic approach to therapy in Crohn's disease has been a "step-up" approach starting with the least toxic agents for mild disease, and increasingly more aggressive treatment for more severe disease, or patients who have not responded to less toxic agents. More recently the field has been moving toward a "top-down" approach (early aggressive management) which might decrease exposure to anti-inflammatory agents and increase exposure to agents that enhance mucosal healing that might prevent future complications.