[Clinical manifestations of Crohn's disease misdiagnosed as appendicitis]

To analyze the clinical manifestations and identify independent diagnostic predictive factors for Crohn's disease (CD) initially diagnosed as appenicitis and treated by surgery.

The medical records of patients diagnosed as acute appendicitis upon admission and treated by surgical operation in the First Affiliated Hospital of Sun Yat-sen University from January 2000 to December 2014 were retrospectively analyzed. Based on postoperative pathological examination and clinical examination results, 28 CD patients were identified (CD group), and for each CD case, 3 controls with confirmed diagnosis of appendicitis were included (appendicitis group, n=84). Clinical manifestations and laboratory examination results of the two groups were analyzed with multivariable Logistic regression to determine independent diagnostic predictive factors for CD initially misdiagnosed as appendicitis.

Altogether 112 patients were enrolled, with a male-to-female ratio of 1.04:1 (57:55), and a median age of 36 years. No significant differences were found in gender, age, and body temperature between the CD group and appendicitis group (all P>0.05). In the appendicitis and CD groups, median duration (Q1-Q3) of abdominal pain was 24 (14-48) hours vs 216 (96-384) hours, proportion of patients with lower right abdominal pain was 98.8% (83/84) vs 75.0% (21/28), proportion of patients with shifting lower right abdominal pain was 98.8% (83/84) vs 7.1% (2/28), proportion of patients with local lower right peritonitis was 95.2% (80/84) vs 53.6% (15/28), proportion of patients with change of bowel emptying habit or stool consistency was 7.1% (6/84) vs 46.4% (13/28), proportion of patients with history of chronic abdominal pain or diarrhea was 10.7% (9/84) vs 75.0% (21/28), preoperative white blood cell count was (14.08±4.13)×10(9)/L vs (8.00±3.42)×10(9)/L, preoperative neutrophil count was (11.34±4.10)×10(9)/L vs (5.58±3.22)×10(9)/L, preoperative hemoglobin was (139.52±19.90) g/L vs (107.65±21.68) g/L, preoperative red blood cell count was (4.85±0.74)×10(12)/L vs (4.28±0.87)×10(12)/L, and preoperative platelet count was (220.68±74.47)×10(9)/L vs (302.09±71.65)×10(9)/L, all with significant differences (all P<0.05). Multivariable analysis showed that change of bowel emptying habit and stool consistency (OR=36.712, 95%CI: 1.672-806.103, P=0.022), medical history of chronic abdominal pain or diarrhea (OR=60.142, 95%CI: 4.501-803.573, P=0.002), lower preoperative hemoglobin level (OR=0.909, 95%CI: 0.858-0.963, P=0.001), and higher platelet count (OR=1.027, 95%CI: 1.007-1.047, P=0.008) were independent predictive factors for CD.

CD should be considered in cases initially diagnosed as appendicitis with change of bowel emptying habit and stool consistency, medical history of chronic abdominal pain or diarrhea, anemia, and increased platelet count.