What initial investigations are recommended for a patient suspected of having necrotizing fasciitis in primary care?

In primary care, for a patient suspected of having necrotizing fasciitis, initial investigations should focus on clinical assessment and urgent referral rather than extensive diagnostic testing.

Initial clinical assessment should include measurement of vital signs such as temperature, heart rate, respiratory rate, blood pressure, level of consciousness, and oxygen saturation if equipment is available and it does not delay treatment. Examination should look for signs such as skin changes, breach of skin integrity, and systemic features suggestive of severe infection or sepsis.

Laboratory investigations such as blood cultures and microbiological samples are typically taken in hospital settings before antimicrobial treatment and are not routinely performed in primary care due to the urgency and severity of necrotizing fasciitis.

Imaging (e.g., X-ray, MRI) is not usually initiated in primary care but may be considered in secondary care to assess the extent of soft tissue involvement.

Urgent referral to secondary care is essential if necrotizing fasciitis is suspected, as this condition requires immediate specialist management including surgical intervention and intravenous antibiotics.

Therefore, the recommended initial approach in primary care is prompt clinical assessment, recognition of severity, and urgent referral for emergency care rather than performing specific investigations locally.

This approach aligns with NICE guidance on suspected sepsis and serious soft tissue infections, emphasizing early recognition, assessment of severity, and urgent transfer to hospital for definitive diagnosis and management ¹,².