A perforated appendix is a life-threatening complication of acute appendicitis, occurring predominantly because of the late recognition and delayed initiation of treatment. A sudden onset of abdominal pain, fever and vomiting must include acute appendicitis as a possible cause. Numerous imaging studies, although useful in confirming appendicitis, have failed to solidify their place in diagnosing perforation, implying that clinical judgment is the most important part during workup.
Acute appendicitis is one of the more important disorders encountered in clinical practice, with more than 250,000 appendectomies performed in the United States on an annual basis   . The primary reason is the life-threatening risk of complications that may arise, the most important one being a perforated appendix  . The clinical presentation of an acute appendicitis is characterized by a sudden onset of mild and cramping abdominal pain in the periumbilical area followed by its progression into a motion-aggravated and severe pain in the right lower quadrant after about 24 hours  . Additional signs include fever (37.2-38.0°C) and anorexia (which is considered to be a diagnostic hallmark), whereas vomiting, altered bowel movements, and voiding difficulties are other notable findings  . Studies have shown that the appendix can often perforate before patients arrive at the hospital and that younger age, as well as longer duration of abdominal pain, are indicative of this event  . Moreover, a very high temperature (> 38.3°C), tachycardia, and profound tenderness of the abdomen have also been documented as possible signs of perforation . Although the differential diagnosis of periumbilical and right lower quadrant pain is broad, acute appendicitis must be suspected early on as delay in diagnosis is the principal reason for mortality rates of a perforated appendix to increase up to 10 times .
A detailed patient history and a thorough physical examination are the cornerstone in the diagnosis of an acute appendicitis and perforation  . Physicians must determine the exact timeline regarding symptom onset, especially abdominal pain, and its location can confirm the diagnosis. Abdominal tenderness at the McBurney point (located in the first third of a line joining the anterior superior iliac spine and the umbilicus) is the most important finding that will suggest appendicitis, while guarding, severe tenderness, and even a localized mass are signs of perforation  . In some patients, abdominal pain can be induced with passive internal rotation of the thigh in flexion and by right hip extension (the obturator and psoas signs, respectively). As soon as an infectious etiology is suspected to be the cause of abdominal pain, laboratory studies comprisingof a complete blood count (CBC) and evaluation of inflammatory parameters is mandatory, as leukocytosis of more than 20,000 cells/mm3 and increased levels of C-reactive protein (CRP) are not only present in acute appendicitis but are also probable signs of perforation  . Additionally, hyperbilirubinemia and the neutrophil-to-lymphocyte ratio (NLR) were identified as key features that suggest a perforated appendix  . The role of imaging studies is questionable when it comes to visualizing a perforated appendix. Ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) have all been identified as efficient methods to diagnose acute appendicitis, with helical CT and MRI showing the highest specificity and sensitivity rates   . Their respective roles in confirming perforation of the appendix, however, have not been confirmed , which is why the diagnosis rests on clinical and laboratory findings.