The ER Diaries: How Lower Leg Pain Signalled a Severe Bacterial Infection

Dr. Zachary Levine gives us the 911 on a 68-year-old man who arrives at hospital with pain in his low leg — and diagnosed with necrotizing fasciitis, otherwise knowns as flesh-eating disease. Here, how they diagnosed and treated the severe bacterial infection.

The Case

A 68-year-old man presented to the ER with pain in his lower leg. The patient was relatively healthy and active, but took medication to treat high blood pressure and cholesterol. He had recently returned from a holiday. His doctor recommended he go to hospital because air travel increases the risk of forming a blood clot, or deep vein thrombosis (DVT).

The Symptoms

Leg pain as a mild ache, but steadily intensified.

The Tests

The problem with DVT is that a blood clot can break off, travel to the lungs and block blood flow there, which is called a pulmonary embolism (PE), and can be life- or limb-threatening. He did not have any other risk factors for DVT, including cancer, trauma, taking hormones or recent surgery. On examination, he looked healthy and was not in distress. Vital signs were all within normal ranges, as were heart sounds; lungs were clear; and abdomen soft and non-tender. But the painful right leg was a bit pink and warm above the ankle, as well as tender to touch.

Blood tests revealed an elevated white blood cell count and a high CRP (an inflammatory marker called C-reactive protein). A Doppler ultrasound was ordered to assess blood flow in vessels, but showed no evidence of a blood clot.  

When the doctor re-examined the patient, he was in significant pain and his vital signs had changed; his heart rate was elevated, temperature had risen and blood pressure had dropped (concerning in someone on medication for high blood pressure). The patient’s lower leg was now very red.

 

 

 
The Diagnosis

 

The presumed diagnosis was cellulitis, or infection of the skin. The patient remembered that he cut his foot on something while walking on the beach. That may be how the bacteria entered his lower leg. Antibiotics were started and the patient was admitted. While cellulitis can be treated effectively with oral antibiotics, the team felt that this aggressive case warranted intravenous antibiotics.

The patient became sweaty and pale, breathing quickly and in severe pain, and rapidly getting worse. The redness covered the entire leg, which had turned purple and blue/grey, and blisters were developing. More blood tests were ordered, as were blood cultures and a CT scan, and an infectious disease specialist and surgeon were requested. The worry was necrotizing fasciitis, a.k.a flesh-eating disease, a very severe bacterial infection that spreads quickly through the flesh.

The latest blood tests indicated severe illness and possible organ dysfunction,  kidney damage or dysfunction. The CT scan showed signs of inflammation, fluid and some air in the soft tissues. But the only way to really diagnose necrotizing fasciitis is by surgical assessment of the tissues.  

 

The Outcome

 

The surgeon took the patient to the OR. Assessment of the tissue showed it to be swollen and dull grey, with a bit of pus, consistent with necrotizing fasciitis. The surgeon rapidly removed the dead tissue, until she got to healthy tissue. The patient was treated with powerful, broad-spectrum antibiotics. He remained in the ICU for five days. In some cases, amputation is required if too much tissue has been destroyed, and to prevent further spread. Fortunately, it was not necessary, and the patient’s condition slowly improved. He was discharged in good condition after 17 days in hospital, able to walk, but still taking oral antibiotics. He is now fully recovered.  

Dr. Zachary Levine is chief of emergency medicine at McGill University Health Centre and associate professor of emergency medicine at McGill.

A version this article appeared in the Oct/Nov 2021 issue with the headline “The ER Diaries,” p. 22.

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