Case Presentation:

A 34-year old male with no past medical history presented to the emergency room with 1 day of low back pain associated with fever and chills.  He reported the pain as constant and 10/10 in severity, partially relieved by ibuprofen. He denied any trauma. There was no loss of bowel or bladder function or other neurological symptoms. He was hemodynamically stable. Physical examination was significant for tenderness on palpation of the lower back along with direct abdominal tenderness of the right lower quadrant. Laboratory was remarkable for leukocytosis of 15.9 with bandemia of 12%. The CXR did not show any infiltrates. Urinalysis was negative for UTI. MRI of the lumbar spine ruled out infectious processes and other spinal abnormalities. CT abdomen with IV contrast revealed subcentimeter focal soft tissue density with minimal surrounding inflammatory changes adjacent to the ascending colon reflective of early acute epiploic appendagitis (AEA). Patient was treated with ibuprofen with resolution of symptoms.

Discussion:

This case aims to increase awareness of this clinical entity and its self-limited course. The epiploic appendices are small fat-filled pouches of peritoneum with unknown function, located along the outside of the colon but are absent in the rectum.  Epiploic appendagitis is a benign and self-limited, yet painful inflammation, of the epiploic appendages that can mimic appendicitis, diverticulitis or cholecystitis.  It is caused by torsion and infarction of the appendices epiploicae along their vascular stalk. Clinical symptoms usually include localized, nonmigratory abdominal pain. Fever and leukocytosis are not present in most cases but can be seen in 15-20% of cases. Back pain is usually not a prominent feature of the presentation but there are case reports of AEA presenting with back pain as seen in this case. When present in the right lower quadrant, the differential diagnosis for tenderness, as seen in this patient, includes both life-threatening as well as benign conditions. These include acute appendicitis, mesenteric adenitis, right-sided diverticulitis, and IBD and a full evaluation is necessary to rule out the more concerning etiologies. Computed tomography is the primary imaging modality for the evaluation of RLQ pain in most patients since it provides a rapid general survey of anatomy and potential pathology. Characteristic CT findings include an oval fatty mass with central streaky densities and surrounded by mesenteric stranding adjacent to the serosal surface of the colon. In addition, mural thickening of the juxtaposed colon can sometimes be observed. Patients with AEA can be managed conservatively with oral anti-inflammatory medications. Complete resolution without surgical intervention usually occurs between 3 to 14 days. 

Conclusions:

Hospitalists should be aware of this rare disease, which mimics many other intra-abdominal acute life-threatening and subacute conditions, such as diverticulitis, cholecystitis and appendicitis. Misdiagnosis of this condition may lead to surgical intervention or antibiotic use which is unnecessary as AEA is a self-limited aseptic condition. Management is conservative with oral anti-inflammatory agents, usually NSAIDs.