What are the key clinical features to consider when diagnosing acute appendicitis in adults?

Key clinical features for diagnosing acute appendicitis in adults include:

• Initial presentation typically involves abdominal pain that often starts as vague periumbilical or epigastric discomfort before localising to the right lower quadrant (right iliac fossa), reflecting the progression of inflammation ¹.
• Associated symptoms commonly include anorexia, nausea, and sometimes vomiting, which usually follow the onset of pain ¹.
• On examination, tenderness localized to the right lower quadrant is a hallmark, often accompanied by guarding and rebound tenderness indicating peritoneal irritation ¹.
• Systemic features such as low-grade fever and raised inflammatory markers (e.g., elevated white blood cell count and C-reactive protein) support the diagnosis but are not solely diagnostic ¹.
• In some cases, especially in elderly patients, pregnant women, or those with atypical presentations, the classical signs may be absent or less pronounced, necessitating a low threshold for further investigation or admission ¹.
• Imaging modalities such as ultrasonography (preferred in children and pregnant women), computed tomography (CT), or magnetic resonance imaging (MRI) can aid diagnosis when clinical features are equivocal, reducing negative appendectomy rates ¹.
• Recent literature emphasizes that no single clinical feature or test definitively confirms or excludes appendicitis; rather, a combination of history, examination, laboratory tests, and selective imaging is essential for accurate diagnosis (Bom et al., 2021).
• Prompt recognition and diagnosis are critical to prevent complications such as perforation, which increases morbidity and mortality ¹.

In summary, the diagnosis of acute appendicitis in adults relies on a constellation of clinical features including characteristic abdominal pain progression, localized right lower quadrant tenderness, systemic inflammatory signs, and supportive laboratory and imaging findings, with special consideration for atypical presentations in certain populations ¹; (Bom et al., 2021).