Appendicitis, an inflammation of the appendix, requires prompt diagnosis to prevent serious complications, such as rupture. The appendix is a small, finger-shaped pouch extending from the large intestine, typically located in the lower right abdomen. If left untreated, an inflamed appendix can burst, spreading infection throughout the abdominal cavity and leading to life-threatening conditions like peritonitis.
Clinical Evaluation
Diagnosis begins with a clinical evaluation. A detailed medical history covers the pain’s onset, progression, and location. Typically, appendicitis pain may start around the belly button before shifting to the lower right side of the abdomen and worsening over several hours. Patients might also report associated symptoms such as nausea, vomiting, loss of appetite, and a low-grade fever.
A physical examination identifies signs of inflammation. The doctor presses on the abdomen to check for tenderness, particularly in the lower right quadrant over McBurney’s point. Rebound tenderness, where pain worsens upon the sudden release of pressure, and guarding, an involuntary stiffening of abdominal muscles, are important indicators of peritoneal irritation. Other maneuvers, such as the Rovsing’s sign (pain in the lower right quadrant when the lower left quadrant is palpated), the psoas sign (pain with hip extension), and the obturator sign (pain with hip rotation), can also provide clues, especially in children.
Laboratory Investigations
Laboratory tests support diagnosis and rule out other conditions. A complete blood count (CBC) is commonly ordered; an elevated white blood cell (WBC) count (leukocytosis) often indicates infection or inflammation. Most adults with appendicitis show an elevated WBC count, often with increased neutrophils. However, it is possible to have appendicitis with a normal WBC count, especially early in the illness.
C-reactive protein (CRP) levels are another important marker; they usually rise within 12-24 hours after symptoms begin and signify inflammation. Urinalysis is performed to check for urinary tract infections (UTIs) or kidney stones, which can cause abdominal pain similar to appendicitis. While an inflamed appendix can irritate the bladder, significant white blood cells or bacteria in urine typically point towards a UTI. For women of childbearing age, a pregnancy test is also performed to rule out ectopic pregnancy, which can present with similar symptoms.
Imaging Scans
Imaging scans provide visual confirmation of appendiceal inflammation. Ultrasound is a non-invasive and radiation-free imaging technique, preferred for children and pregnant women. An ultrasound can reveal an enlarged appendix (typically 6 millimeters or more in diameter), fluid around it, or an appendicolith. Its accuracy varies and is highly dependent on operator skill, and it can be challenging in larger patients.
Computed Tomography (CT) scans are highly accurate and frequently used in adults, providing detailed cross-sectional images. A CT scan shows an enlarged appendix (greater than 6 mm), thickened walls, or inflammation in surrounding fatty tissue. CT scans have a high diagnostic accuracy and can help identify other causes of abdominal pain. Although CT scans involve radiation exposure, their detail often allows for a more definitive diagnosis.
Magnetic Resonance Imaging (MRI) is useful when ultrasound is inconclusive, especially in pregnant women and children, as it does not use ionizing radiation. MRI provides detailed soft tissue images, and its diagnostic accuracy is comparable to CT. It identifies signs of inflammation like an enlarged appendix or fluid collections. Despite its benefits, MRI may be less readily available and can take longer than a CT scan.
Confirming the Diagnosis
Confirming appendicitis involves integrating clinical evaluation, laboratory investigations, and imaging scans. No single test can definitively diagnose appendicitis, as symptoms can mimic other abdominal conditions. Healthcare providers combine symptoms, physical findings, and test results for a comprehensive picture. Imaging studies like ultrasound, CT, or MRI provide crucial visual evidence to confirm or rule out appendicitis.
The combination of a classic presentation of symptoms, elevated inflammatory markers, and characteristic findings on imaging greatly increases diagnostic certainty. This multi-faceted assessment helps differentiate appendicitis from other conditions causing similar pain, such as urinary tract infections, kidney stones, or gynecological issues. Once a diagnosis of appendicitis is confirmed, surgical removal of the appendix is typically the next step to prevent complications.