Painful swollen foot with discharging blisters.
A previously well woman had a progressively painful and swollen right foot over the past one week. She presented to the accidents and emergency department with a cellulitic foot associated with two blisters which were discharging pus over the lateral malleolus and heel. She was tachycardic, pyrexic and had a raised white cell count of 36 and c-reactive protein count of 606. Plain radiographs of her leg and foot revealed gas in her soft tissues. A swab sample was taken and antibiotics of flucloxacillin, ciprofloxacin and metronidazole were commenced. Patient was then taken to theatre the same evening for a below knee amputation. She recovered well postoperatively. The amputation wound was closed 48 hours later after showing no signs of muscle or soft tissue necrosis. The swab sample grew staphylococcal aureus.
Gas gangrene is usually caused by the clostridium species, most commonly clostridium perfringens. It can also be from Group A Streptococcus, Staphylococcus aureus and vibrio vulnificus. The disease is characterised by rapid onset of myonecrosis, gas production and sepsis. These species are gram-positive, spore-forming and anaerobic rods and often cause disease in the trauma and surgical setting. They can also occur spontaneously, most often caused by haematogenous spread of clostridium septicum from the gastrointestinal tract . Not all wounds contaminated by clostridia develop gas gangrene. The myonecrosis develop when sufficient devitalised tissue is present to support anaerobic metabolism. The bacteria releases exotoxin which hydrolyses cell membranes, causes occlusive microvascular thrombosis and lead to tissue necrosis. The products of tissue breakdown, eg. creatine phosphokinase, myoglobin, cause secondary toxicity. Physical findings are usually tachycardia, fever, pale-grey skin discolouration, crepitus, blisters, wound discharge and tense oedema. X-ray, CT scan and MRI of the area may show gas in the tissues. Early diagnosis and aggressive treatment involving resuscitation, urgent surgical debridement and antibiotics are important to prevent the high morbidity and mortality associated with this disease.
Gas gangrene
Based on the provided X-ray images of the lower limbs and feet, the following main observations can be noted:
Combining the clinical presentation of a 56-year-old female with foot pain and swelling, accompanied by blisters (possibly ruptured), and the radiological sign of suspected gas in the soft tissue, the following diagnoses are considered:
Considering the patient’s age, the condition of the foot wound (pain, swelling, drainage, and bullae), the clear presence of soft tissue gas on imaging, and the high clinical suspicion of Clostridium or other anaerobic bacterial infections, the most likely diagnosis is:
Gas Gangrene (Clostridial Myonecrosis).
This condition progresses rapidly and, without timely treatment, carries a high mortality rate. While necrotizing fasciitis or other severe anaerobic infections must also be considered, gas gangrene aligns most closely with both the clinical and imaging findings.
After acute infection control and passing the critical stage, progressive rehabilitation exercises should be introduced. The following recommendations are in accordance with the FITT-VP principle:
During the entire rehabilitation process, if the patient has osteoporosis, diabetes, or poor cardiopulmonary function, exercise intensity should be appropriately reduced and closely monitored to prevent complications.
This report is based on the currently available limited information for reference purposes and cannot replace an in-person consultation or professional medical advice. Patients must seek further examinations and treatment under the guidance of a specialized physician.
Gas gangrene
