Delayed diagnosis of appendicitis in children treated with antibiotics.

The diagnosis of appendicitis in children can be difficult. Misdiagnosis may result in empirical treatment with antibiotics. The aim of this study was to determine whether initial treatment with antibiotics hindered subsequent diagnosis of appendicitis. Retrospective review of 311 children treated for appendicitis between 1999 and 2004. Patients were divided into two groups: Group 1: (n = 45) received antibiotics prior to a definitive diagnosis of appendicitis. Group 2: (n = 266) did not receive antibiotics prior to a diagnosis of appendicitis. Group 1 patients were significantly younger and more likely to be female than in group 2. Abdominal tenderness was less marked and there was a greater reliance on radiological investigations in patients receiving antibiotics. C-reactive protein and pre-operative temperature were significantly higher in group 1 patients compared to group 2. The perforation rate and complication rate were significantly greater in group 1. The commonest misdiagnoses were urinary tract infection and respiratory infection. Initial misdiagnosis results in significant delay before appendicectomy. This study shows that the clinical signs of acute appendicitis can be masked by prior treatment with antibiotics. The diagnosis of acute appendicitis must be considered and, if necessary, excluded in all children seen with abdominal pain who have recently been treated with antibiotics.