eosinophilic gastroenteritis is an uncommon disease that 's pathologically characterized by marked eosinophilic infiltration in any area of the gastrointestinal tract without the presence of parasitic infections , drug reactions or malignancy . since it was first described in 1937 by kaijer1 ) , approximately 300 cases have been reported worldwide by 19962 ) and there have been korean 31 cases3 ) . the clinical manifestations are related to the site of gastrointestinal ( gi ) involvement and the layer of the involved bowel wall4 ) . to the best of our knowledge , eosinophilic enteritis presenting as intussusception in adult has not been reported in the literature . a previously healthy 55-year - old korean male was admitted to our hospital with a 7 day history of intermittent left abdominal pain without nausea , vomiting , diarrhea or hematochezia . the man 's pain had intensified and loose stool had occurred over the previous 24 hours . he had no history of medications , atopy or food allergy . the physical examination on admission revealed an acute ill appearance , but the patient was alert and mentality orientated . his body temperature was 36.8 , the blood pressure was 130/90 mmhg , the pulse 80/min and the respiratory rate 18/min . he was tender upon palpation in the left mid abdomen ; he had no rebound tenderness . laboratory investigation revealed a white blood cell count of 9,100/mm with 16.8% eosinophils , an eosinophil count of 1,824/mm , a hemoglobin level of 14.1 g / dl , a prothrombin percentage of 51% and an international normalized ratio ( inr ) of 1.72 . the serum total protein (= 7.3 g / dl ) and albumin (= 4.2 g / dl ) were within the reference ranges . the chest radiograph was within normal limits , and the abdominal film revealed a nonspecific bowel gas pattern . abdominal ultrasound demonstrated a central echogenic core surrounded by a hypoechoic rim in the left midabdomen ( figure 1a . the longitudinal section demonstrated jejunojejunal intussusception ( figure 1b ) . computed tomography scanning demonstrated diffuse circumferential wall thickening at the duodenal bulb and jejunum , and this was combined with short segmental enteroenteric intussusception ( arrow ) without a definite mass or any enlarged lymph nodes ( figure 2 ) . however , we could not rule out a small bowel mass as a leading point of intussusception in this adult . it showed only diffuse mucosal edema and erythematous change at the jejunum without a mass lesion ( figure 3 ) . a stool exam , a serologic test for parasitic infection via micro - elisa and the serum ige level ( 42.8 iu / ml , normal range : 0~170 ) were all within the normal ranges . esophagogastroduodenoscopy and colonoscopy showed normal mucosa except for mucosal edema and the erythematous change at the duodenum . histologically , normal mucosa was observed at the terminal ileum , cecum , ascending colon , transverse colon , descending colon , sigmoid colon , rectum , gastric antrum , body and fundus . at the duodenum , a diffuse infiltration by inflammatory cells and mainly eosinophils ( more than 20/high power field ) were observed . in addition , there were extracellular eosinophilic granules in the lamina propria , and eosinophils in the epithelium were also observed ( figure 4 ) . his abdominal pain was improved and the follow up eosinophil count after 7 days medication was within the normal range . eosinophilic gastroenteritis is defined as a disorder that selectively affects the gastrointestinal tract with eosinophil - rich inflammation in the absence of any known causes for this eosinophilia such as drug reactions , parasitic infections or malignancy . the clinical manifestations vary according to the site of the eosinophilic infiltrated layer of the bowel wall . klein et al.4 ) classified it into three forms based on the dominantly involved layer of the bowel wall ( e.g. the mucosal , muscular and subserosal types ) . in the mucosal type , symptoms such as diarrhea , hematochezia and cramping abdominal pain usually occur , which are similar to those of inflammatory bowel diseases . in the other hand , thickening of the muscular layer in the muscular type narrows the intestinal lumen and leads to intestinal obstruction or perforation . therefore , eosinophilic gastroenteritis should be considered in the differential diagnosis for the above mentioned , unexplained gastrointestinal signs and symptoms . most patients with this disorder can be treated successfully without surgical therapy if the correct diagnosis is made . although in our case the dominant affected layer of the bowel wall was not confirmed histologically , it was thought to be the muscular type based on the clinical feature of the muscular type ( intussusception ) , and there was no diarrhea of the mucosal type or ascites of the subserosal one . however , some gi symptoms and eosinophilic infiltration of the gi tract without involvement of other organs such as heart or cns may support the diagnosis . the presence of food allergy and peripheral eosinophilia are not required for the diagnosis6 ) . although a normal esophagus is devoid of eosinophils , the rest of the gastrointestinal tract contains readily detectable eosinophils . thus , differentiation of eosinophilic gastroenteritis from the normal condition relies on several factors , including eosinophil quantification and comparisons with the normal values at each medical center , the location of the eosinophils ( e.g. their presence in abnormal positions such as he intraepithelial , superficial mucosal and intestinal crypt regions ) , the presence of extracellular eosinophilic staining constituents ( often free granules ) , and the absence of pathologic features suggestive of other primary disorders ( e.g. neutrophilia associated with ibd or vasculitis associated with churg - strauss syndrome)6 ) . our patient , who had no history of medications , atopy or food allergy , presented with intussusception together with peripheral eosinophilia and a typical eosinophilic infiltration of the gi tract without involvement of the other organs ( figure 4 ) . intussusception is an extremely rare complication of eosinophilic gastroenteritis and only 4 childhood cases of this disease have been reported so far7 - 10 ) . however , eosinophilic enteritis presenting as intussusception in adult has not been reported in the literature . intussusception remains a rare condition in adults , and it represents 1% to 3% of all bowel obstructions11 ) . in adults , acute intestinal obstruction is not common and most patients present with subacute , chronic or intermittent symptoms . the classic clinical triad of conventional intussusception consists of abdominal pain , a palpable sausage - shaped mass and occult blood positive stool , but this complete spectrum of signs is rarely present12 ) . our patient only has an intermittent cramping abdominal pain for about a week , yet based on ultrasonography , the correct diagnosis of intussusception was easy to make . because a demonstrable etiology can be found in 70% to 90% of the adult cases of intussusceptions , and about 40% of them are caused by a primary or secondary malignant neoplasm11 - 13 ) , we performed ct and capsule endoscopy . the ct scan revealed diffuse circumferential wall thickening at the duodenal bulb and jejunum , and this was combined with short segmental jejunojejunal intussusception without a definite mass or any enlarged lymph nodes . capsule endoscopy also showed only diffuse mucosal edema and erythematous mucosal change at the jejunum without a mass lesion . the patient was diagnosed as suffering with intussusception due to eosinophilic gastroenteritis , and he was treated with oral prednisolone at 30 mg / day . from the therapeutic point of view , an appropriate therapeutic approach includes a trial of food elimination if sensitization is found on the basis of food skin testing , radioallergosorbent testing ( rast ) or both . however , because no sensitization was found , we choose the anti - inflammatory drug prednisolone . drugs such as ketotifen , montelukast , sodium cromoglycate or alternative chinese medicines have been advocated , but controlled trials are lacking for any therapies14 - 17 ) . our patient 's abdominal pain and tenderness were dramatically improved and this disappeared after 7 days of medication ; the eosinophil count was normalized . the natural history of eosinophilic gastroenteritis has not been well documented , but regular evaluation with endoscopy and abdominal ultrasonography , and obtaining the eosinophil count are necessary due to the chronic waxing and waning nature of this disorder . in addition , routine surveillance of the cardiopulmonary systems is recommended6 ) because these diseases can often be a manifestation of another primary disease process . for our patient , we report here on a first case of eosinophilic enteritis that presented as intussusception in a 55-year - old man .