What are the key clinical signs and symptoms to consider when diagnosing peritonitis in a primary care setting?

Key clinical signs and symptoms to consider when diagnosing peritonitis in a primary care setting include:

• Severe abdominal pain that is often sudden in onset, persistent, and worsens with movement or coughing, indicating peritoneal irritation NICE CKS.
• Abdominal tenderness on palpation, especially with guarding or rigidity, reflecting inflammation of the peritoneum NICE CKS.
• Rebound tenderness, where pain increases upon release of pressure, is a classic sign of peritoneal inflammation NICE CKS.
• Systemic signs such as fever, tachycardia, and signs of sepsis may be present, indicating a systemic inflammatory response NICE CKS.
• Nausea, vomiting, and anorexia are common accompanying symptoms due to gastrointestinal irritation NICE CKS.
• Altered bowel sounds, often reduced or absent, may be noted due to paralytic ileus secondary to peritoneal inflammation NICE CKS.
• Signs of localized peritonitis may mimic other acute abdominal conditions such as appendicitis, as highlighted by cases of primary peritonitis caused by Streptococcus pneumoniae presenting similarly Cortese et al. 2019.

In primary care, a high index of suspicion is essential when these signs and symptoms are present, especially if the patient appears systemically unwell or has risk factors for intra-abdominal infection. Early recognition and urgent referral for hospital assessment are critical due to the potential severity of peritonitis NICE CKS Cortese et al. 2019.