Initially recognised as a rare disorder, Crohn's disease became a more common health problem in the industrialised world during the 1970s. During the 1980s the number of patients seemed to stabilise. However, most recent reports indicate an increase in numbers of newly diagnosed cases of Crohn's disease, especially among children and teenagers.
Clearly, both Crohn's disease and Ulcerative colitis are caused by a combination of factors. Twin studies from Sweden, Denmark and the UK have demonstrated that genetic factors explain approximately 20-50% of Crohn's disease cases. This would suggest then, that at least 50% of cases are caused by alternative factors, not relating to genetic inheritance. The most obvious environmental risk factor is cigarette smoking, with a two-fold lifetime risk for smokers to develop Crohn's disease as compared to non-smokers. Furthermore, smokers tend to have a more severe course of the disease than non-smokers and also less benefit from medication.
As with a wide range of diagnoses, the first case reports of inflammatory bowel disease date back to the Hippocratic writings, although it is impossible to make a statement regarding the exact diagnosis based on these reports.
In 1932 Drs. Crohn, Ginzburg and Oppenheimer, from Mount Sinai Hospital, New York published their report on a new disease entity, regional enteritis. This became known as Crohn's disease. It was not until 1960 that it was recognised that Crohn's disease could also involve the colon. This is known as Crohn's colitis.
Typically people with Crohn's disease have recurrent attacks, with acute exacerbations interspersed with periods of remission or less active disease. Whether a relapse means the recurrence of symptoms or the appearance of mucosal abnormalities before the development of symptoms remains the subject of dispute.
There are several clinical symptoms associated with Crohn's disease. Diarrhoea is a typical feature in the majority of patients. Rectal bleeding occurs in approximately 30% of cases. Loss of appetite, weight loss and abdominal pain are common symptoms. In the more severe active state, fever and fatigue are often present.
Approximately 10% of Crohn's patients have disease manifestation outside of the gastrointestinal tract. The most common non-gastrointestinal manifestations are joint pain and inflammation. More rarely the skin, eyes or liver may be involved.
Diagnosis of Crohn's disease is based on a typical medical history in combination with endoscopic or radiological examination. Blood samples can reveal signs of ongoing inflammation and stool specimens may be needed in order to exclude an infectious origin.
Aminosalycylates: Are considered safe, but with limited effect in severe Ulcerative colitis. Despite this profile, Aminosalycylates are considered to be a first-line drug, especially in mild forms of the disease.
Steroids: Have shown to be effective in the short-term perspective in inducing remission. Steroids are not used in maintenance therapy due to lack of effect in combination with high risk of side effects.
Immunosuppressants: Less documentation is available regarding immunosuppressant role in Ulcerative colitis compared to Crohn's disease. Due to a more pronounced risk for severe side effects, immunomudulators are regarded as third-line drugs.
Biologics: A TNF inhibitor is a pharmaceutical drug that suppresses response to tumour necrosis factor (TNF), which is part of the inflammatory response.
GMA apheresis: Is a non-pharmacological approach aimed at reducing the ongoing inflammation by removing over-activated white blood cells from the blood circulation, thereby reducing the inflammatory burden, without the risk of side effects attributed to drugs.
Surgical treatment: In approximately 50% of CD patients, surgical intervention will be needed at some time. It is believed that recent advances in the treatment of Crohn's will reduce the number of patients in need of surgery.
1. Baumgart DC, Carding SR. The Lancet 2007;369:1627-1640.