What are the clinical signs of peritonitis?

Clinical Signs of Peritonitis

The key clinical signs of peritonitis include abdominal rigidity on palpation, abdominal pain with tenderness, and fever, though critically, up to 30% of patients may present with minimal or no classic peritoneal signs. 1, 2

Primary Clinical Findings

Classic Presentation

• Abdominal rigidity and guarding are the most reliable positive palpatory findings when peritonitis is suspected 3
• Abdominal pain with tenderness is present in the majority of cases 2
• Fever occurs in approximately 71% of patients (15 of 21 cases in documented series) 2

Critical Caveat: Silent Presentations

Many patients, particularly those with cirrhosis and spontaneous bacterial peritonitis, may present without any peritoneal signs 4, 2. In these cases, look for:

• Clinical worsening or deterioration without obvious cause 2
• Hepatic encephalopathy (new or worsening) 2
• Rising serum creatinine levels 2
• Therapy-resistant ascites 2

Associated Clinical Features

Gastrointestinal Manifestations

• Changes in gastrointestinal motility including nausea, vomiting, or diarrhea 4
• Ileus may develop 4
• Diarrhea was present in approximately 24% of cases 5

Systemic Signs

• Weight loss occurs in approximately 29% of patients 5
• Colic or colicky abdominal pain was documented in 86% of cases 5

Distinguishing Localized vs. Diffuse Peritonitis

The distribution of peritoneal signs has critical prognostic and management implications 1:

Localized Peritonitis

• Rigidity confined to a specific abdominal sector 1
• May allow time for further diagnostic evaluation before intervention 1

Diffuse Peritonitis (Peritonism)

• Generalized rigidity throughout the abdomen 1
• This is an ominous finding requiring immediate surgical exploration with very few exceptions 1

Important Diagnostic Limitations

Negative palpatory findings have little value in excluding peritonitis 3. The absence of rigidity or guarding does not rule out significant intra-abdominal pathology, particularly in:

• Immunocompromised patients
• Elderly patients
• Those with cirrhosis and ascites 4, 2

Digital rectal examination adds no diagnostic value for peritonitis 3

Clinical Context Matters

The presentation varies by etiology 1:

• Primary peritonitis (spontaneous bacterial peritonitis in cirrhotic patients): Often subtle or absent peritoneal signs 4, 2
• Secondary peritonitis (from GI perforation or infected viscera): More likely to present with classic findings 1
• Tertiary peritonitis (recurrent/persistent): May have attenuated signs due to prior interventions 1