Gastrointestinal symptoms in Beçhet's disease include vomiting, abdominal pain, flatulence, diarrhoea and constipation.4 9
It is more common in patients from the far East than from Europe.2
The ethnic and geographical variation in the distribution of symptoms associated with Beçhet's disease could provide clues to the genetic basis of this condition. No single causative gene for Beçhet's disease has yet emerged, although it exhibits a marked association with human leukocyte antigen-B51.2
The progression of mild abdominal symptoms to fistula formation within a year demonstrates the unpredictability of Beçhet's intestinal disease progression. Our patient had a long history of Beçhet's disease before rapidly developing gastrointestinal symptoms years later. Only one case of fistula formation 2 months after initial presentation has been described to date.10
It is widely accepted that gastrointestinal symptoms do not develop before the major criteria of the syndrome (as defined by an international study group in 1990) are satisfied.4
In general, gastrointestinal symptoms develop around 6 years after first presentation.11
The diagnosis of Beçhet's disease is often delayed as initial symptoms may not be immediately recognised as part of the constellation making up the syndrome. Patients often have Beçhet's disease long before diagnosis and so the development of RVF 2 months after diagnosis (as in the case mentioned above10
) could be an artefact of delayed diagnosis.
A case of RVF in a Beçhet's disease patient after episiotomy has been previously described.12
In this case, surgical management using diversion colostomy and two advancement flap procedures failed to resolve the fistula. Infliximab was subsequently used until the fistula resolved and a mucosal flap was created.12
However, in our patient, the fistula developed in the setting of treatment with infliximab. Continuation of this drug was therefore abandoned in favour of surgical management.
The gastrointestinal and systemic features of Beçhet's disease and inflammatory bowel diseases (especially Crohn's disease) overlap considerably, thus posing a diagnostic challenge.13 14
There are reported cases of Beçhet's intestinal colitis mimicking Crohn's disease but without the typical granulomatous inflammation.14
There are other reports that support the possibility of co-existent Beçhet's colitis and Crohn's disease in one patient.7
Systemic manifestations of both conditions are remarkably similar. Uveitis, oral aphtous ulcers, erythema nodusum and arthritis are features of both diseases. However, urogenital ulcers tend to occur frequently in Beçhet's but rarely, if ever, in Crohn's disease. Colonoscopic appearance can sometimes be inconclusive as longitudinal ulcers and the cobblestone mucosa appearance previously associated with Crohn's have also been noted in Beçhet's disease.13 14
The only way to reliably distinguish between these conditions is histopathology (). Transmural inflammation is a hallmark of both conditions but granuloma formation, lymphoid aggregates and submucosal fibrosis are rarely found in Beçhet's disease.
Histopathology slide of resected colon. The transmural inflammation and punched out lesion specific of Beçhet's disease is shown.
- Beçhet's intestinal disease is an unusual cause of rectovaginal fistula, so other possibilities must be excluded.
- Surgical treatment should not be delayed in cases where medical therapy does not yield anticipated results.
- The possibility of concurrent Crohn's disease and Beçhet's disease in the same patient means histopathology remains the definitive mode for establishing diagnosis.