The diagnosis is often based on history and examination, supported by deranged observations and abnormal investigations in keeping with sepsis. Point of care tests such as venous blood gases and full blood counts may help in convincing reluctant specialists, however if Fournier’s is in the differential, then early escalation to a ED senior is needed, both for direct clinical care and in timely referral and acceptance by specialties.

Where blood tests are being requested, key investigations include blood cultures, VBG, CRP and FBC. U&Es and LFTs are helpful to assess the current clinical picture and provide reference for ongoing critical care and resuscitation. These patients can be very unwell and early critical care escalation, whilst the fundamentals have been well addressed by the ED, is warranted.

Potentially ultrasound or x-ray may show subcutaneous emphysema, pathognomonic of Fournier’s in the clinical context. If the patient were to have cross sectional imaging, this would likely show a clearer extent of the infection’s spread (be wary that infection can spread at the rate of centimetres within the hour and imaging should not delay referral).