Haemorrhagic colitis has many different etiologies, including infectious colitis with either bacterial or parasitic infections. Other causes include ischaemic colitis, as well as inflammatory bowel disease such as Crohn's colitis and ulcerative colitis. Eosinophilic colitis (EC) is a rare cause of colitis; however, it may very occasionally present with haemorrhagic manifestations.
Primary eosinophilic gastrointestinal disease (EGID) was first described by Kaiser in 1937 [3
]. It is a rare chronic inflammatory bowel condition of unknown etiology, characterized by inflammatory changes rich in eosinophils without evidence of other known causes of eosinophilia. This may affect any segment of the gastrointestinal tract and presents in a myriad of different manifestations.
Causes of EC may be divided into 2 main groups, that is, those with primary and secondary causes. Primary eosinophilic colitis is the rarest manifestation of EGID, the other more common presentations being eosinophilic esophagitis and eosinophilic gastroenteritis [4
]. The disease mainly affects the paediatric population, although it has been reported in the adult population as well. The hallmarks of EC are peripheral eosinophilia, segmental eosinophilic colonic infiltration, and functional abnormalities [5
]. Secondary causes of EC include parasitic infection, inflammatory bowel disease, carcinoma, connective tissue disease, drug-related causes such as Rifampicin, Clozapine, and Carbamazepine, and vasculitic causes.
Clinical presentation of the primary EC depends on the layer of intestinal wall that is infiltrated by eosinophils and correlates well with the physical symptoms and clinical findings. Mucosal predominant disease presents with diarrhoea, protein wasting, and malabsorption [6
]. Transmural disease is associated with thickened bowel, obstruction, perforation, volvulus, intussusception [7
], and perforation [8
]. Serosal involvement is characterized by presence of eosinophilic ascites [9
]. However, there has been no report so far in the literature on eosinophilic colitis presenting with haemorrhagic colitis.
The diagnosis of EC is made via the presence of symptoms, peripheral eosinophilia, endoscopic or histological findings, and eosinophilic ascitis, with exclusion of all other causes of secondary eosinophilia. Histological findings show eosinophilic infiltrates throughout the lamina propria, with extension through the muscularis mucosa into the submucosa. Crypt abscesses and lymphonodular hyperplasia may also be evident [10
Treatment of EC has not been well established due to the low numbers of reported cases worldwide. In neonates, there has been some beneficial effect of withdrawing specific food triggers for cases with food allergies; however, in adults, the response of dietary modification is less clearer. In patients who present with abdominal symptoms, firstly indications for surgical exploration must be ruled out, such as free intraabdominal air, volvulus, obstruction, or peritonitis. Patients who present as such should be urgently brought to the operating theater for a laparotomy and assessment of the bowel intraoperatively, and resection with or without primary anastomosis depending on the intraoperative findings. In all other patients with no such indications, corticosteroids have been found to be effective for symptom control in EC [11
]. The majority of cases respond within 2 weeks of treatment; however, relapse is frequent and may require recurrent courses which may lead to steroid dependence. Budesonide has been shown to be effective in cases of EC, particularly in the right colon [13
]. However, it must be emphasized again that surgical indications, as well as parasitic infection and drug causes, are essential to be ruled out before starting corticosteroids, as in these cases, treatment will certainly worsen the patient's condition.
In the above-mentioned case, the patient was extensively worked up and treated empirically for various infective causes of haemorrhagic colitis. Unfortunately, he rapidly deteriorated and developed ischaemic haemorrhagic bowel which necessitated emergency surgery, only after which the diagnosis of eosinophilic colitis was made on histological examination of the resected specimen.