Abstract
Eosinophilic enteritis is a rare entity affecting the gastrointestinal tract. Majority of the times, it affects the stomach and jejunum. We report a case of 56 year old female, whose presentation mimicked that of ileocaecal tuberculosis. Exploratory laparotomy with right hemicolectomy was done, histopathology of the specimen confirmed eosinophilic enteritis. Discussion with respect to Indian population in whom ileocaecal tuberculosis is common is presented.

Introduction
Eosinophilic gastroenteritis characterised by eosinophilic infiltration into one or more layers of the gastrointestinal tract is a rare clinico-pathological entity. It was first decribed in 1937 by Kaijser¹ and since then has been occasionally reported as case reports or small case series. An increased incidence has been observed in countries like Korea and China.²

Though pathogenesis is poorly understood, 40% have been found to have an allergic basis.3 We present a case of 56 year old female with eosinophilic enteritis.

Case Report
A 56 year old female presented to us with severe colicky pain in abdomen radiating from right loin to groin, associated with nausea and anorexia with no aggravating or relieving factors. She gave history of renal stone with medications for the same in the past and history of appendicectomy done 10 years back.

Clinical examination revealed mild distension of abdomen with tenderness in right iliac fossa with no organomegaly. Mild tenderness was present in the right fornix per vaginum and no abnormality detected per rectum.

Routine haematological and biochemical investigations revealed a markedly increased erythrocyte sedimentation rate (ESR) of 104 mm/hr with no peripheral eosinophilia, other values were within normal limits.

Plain X-ray of abdomen was unremarkable. Ultrasonography revealed a collection of fluid with mucosal thickening and enlarged ileocolic nodes. CT scan reported an ill defined collection in pelvis, in the midline and to the right, enlarged ileocolic lymph nodes with wall thickening and mucosal irregularity of one of the distal loops, the lesion touching the right adnexal region, was suggestive of an infective process, most probably tuberculosis in view of increased ESR
(Fig. 1).

The patient was taken for exploratory laparotomy, on which an ileoceacal mass along with enlarged ileocolic lymph nodes was found. Right

Fig. 1 : CT scan showing bowel wall thickening of the distal ileal loops (left) and enlarged ileocolic lymph nodes (right).

Hemicolectomy along with removal of enlarged ileocolic lymph nodes and Ileo-transverse anastomosis was performed. Patient recovered well and discharged on 7th post operative day.
Histopathology of the sections revealed eosinophilic enteritis showing dense fibrosis of serosa and transmural inflammatory infiltrate rich in eosinophils. Mesenteric lymph nodes were reactive in nature. There was no evidence of tuberculosis or malignancy. Postoperative follow up of six months has shown her to be disease free.

Discussion
Eosinophilic gastroenteritis being a rare clinico-pathological finding, may often be misdiagnosed, especially because of its varied clinical presentation, which in fact is dependant on predominant site and layer of involvement. It can be broadly classified as mucosal disease, having colicky pain, nausea, vomiting and weight loss; muscularis disease with pyloric or intestinal obstruction and serosal disease with eosinophilic ascites.4 Ours was a transmural involvement, which presented to us with colicky pain and without weight loss.

Diagnostic criteria include presence of gastrointestinal symptoms, an eosinophilic infiltrate on operative or biopsy specimen, absence of parasitic infection, no eosinophilic disease outside the gastrointestinal tract and exclusion of Crohn's disease, lymphoma and other tumours.5 In our case, the diagnosis was confirmed on histopathological report of the specimen.

Peripheral eosinophilia is not included in the criteria, as in about 20% of cases it is absent.5 Our case did not have peripheral eosinophilia.

The pathogenesis of eosinophilic enteritis is still unknown, but speculation has focused on the selective release of eosinophil major proteins leading to intestinal epithelial damage. An allergic basis for this entity has also been proposed due its presence in about 40% patients.3 In India, worms present in low socioeconomic groups can be one of the factors, however, this remains to be proved.

In India, a patient presenting with an ileoceacal mass of infective aetiology with a raised ESR is often diagnosed as ileocaecal Kochs, we suggest a histopathological proof before doing so.

The role of steroids, sodium cromoglycate and other immunosuppressants in eosinophilic enteritis is not well estabilished, however, in few cases, especially those which have been diagnosed pre-operatively and have minimal abdominal symptoms, they have produced symptomatic improvement. We did not use steroids due to the high probability of our case being ileocaecal Kochs.

The long term outlook for eosinophilic gastroenteritis patients is generally favourable i.e. mortality related to disease is rare. It does not predispose for carcinoma of the gastrointestinal tract. However, a degree of clinical suspicion is advisable, in chronic and unexplained abdominal symptoms, especially in an Indian setup, to avoid confusion with tuberculosis.

References

1. Kaijser R. Zurkenntnis der allergisschen des verdauungskabals vonstandpunkt des chiruugan aus. Arch Klin Chir 1937; 36 : 188.
2. Kim NI, Jo YJ, Song MH, et al. Clinical features of eosinophilic gastroenteritis: Korean J Gastroenterol 2004 Oct; 44(4) : 217-23.
3. Talley NJ, Shorter RG, Phillips SF, Zinsmeister AR. Eosinophilic gastroenteritis; a clinicopathological study of patients with disease of mucosa, muscle layer, and sub-serosal tissue. Gut 1990; 31 : 54-8.
4. Karande TT, Oak SN, Trivedi AA, et al. Proximal jejunal obstruction due to eosinophilic gastroenteritis. J Postgrad Med 1996; 42 : 121-3.
5. Chen MJ, Chu CH, Lin SC, Shih SC, Wang TE. Eosinophilic gastroenteritis: Clinical experience with 15 patients ISSN 1007-9327 CN 14-1219/R. World J Gastroenterol  2003 December; 9 (12) : 2813-6.