There is limited data to compare the clinical characteristics and recurrence rates between left-sided primary epiploic appendagitis (PEA) versus left-sided acute colonic diverticulitis (ACD), and right-sided PEA versus right-sided ACD, respectively.We retrospectively reviewed the medical records and radiologic images of the patients who presented with left-sided or right-sided acute abdominal pain and had computer tomography performed at the time of presentation showing radiological signs of PEA or ACD between January 2004 and December 2014. We compared the clinical characteristics of left PEA versus left ACD and right PEA versus right ACD, respectively.Fifty-six patients (left:right = 27:29) and 308 patients (left:right = 24:284) were diagnosed with symptomatic PEA and ACD, respectively. Left-sided PEA were statistically significantly younger (50.2 ± 15.4 years vs. 62.1 ± 15.8 years, P= 0.009), more obese (body mass index [BMI]: 26.3 ± 2.9 kg/m2 vs. 22.3 ± 3.1 kg/m2 , P< 0.001), and had more tendencies with normal or mildly elevated high-sensitivity C-reactive protein (hsCRP) (1.2 ± 1.3 mg/dL vs. 8.4 ± 7.9 mg/dL, P< 0.001) than patients with left-sided ACD. The discriminative function of age, BMI and CRP between left-sided PEA versus left-sided ACD was 0.71 (cutoff: age ≤ 59 years, sensitivity of 66.7%, specificity of 77.8%), 0.83 (cutoff: BMI > 24.5 kg/m2 , sensitivity of 80.0%, specificity of 80.0%) and 0.80 (cutoff: CRP < 1.8 mg/dL, sensitivity of 72.2%, specificity of 85.7%).If patients with left lower quadrant abdominal pain are less than 60 years, obese (BMI > 24.5 kg/m2 ) with or without normal to mild elevated CRP levels (CRP < 1.8 mg/dL), it might be necessary for clinicians to suspect the diagnosis of PEA rather than ACD.
