May 2017 | Case of the Month

The patient was admitted to hospital with the diagnosis of possible early necrotising fasciitis, a diagnosis which was later confirmed.

Necrotising fasciitis (NF) is an uncommon but rapidly progressive and life-threatening infection of the deep dermis, adipose tissue and subcutaneous fascia.

The most widely broadcast cases of necrotising fasciitis are caused predominantly by group A streptococci, and sometimes by staphylococcus aureus and other organisms. While the portal of entry is thought to be an open wound, such a finding may not be apparent. Other forms of necrotising subcutaneous infections include clostridial cellulitis (gangrene), and those resulting from multiple organisms, one of which is usually an anaerobe. Clostridial infections usually follow significant injury or surgery and result in gas under the skin, which clinically is felt as crepitus.

An early diagnosis of NF is vital in terms of reducing morbidity and mortality. NF should be suspected in the following scenarios:

• If the level of pain and tenderness, or systemic upset, is out of proportion to the physical signs
• Dusky-violaceous areas along with erythema
• Crepitus
• Over a short period of time blisters develop, the affected area becomes necrotic, and the patient very toxic

Patients require urgent surgery to remove affected tissue, and high-dose antibiotics. If diagnosed and treated early, most patients will survive with minimal scarring. However if there is significant tissue loss, later skin grafting will be necessary and in some patients amputation of limbs is required. Up to 25% of patients will die from the disease.

Please refer to the relevant chapter on NF, cellulitis and erysipelas for more information.