Skip to content

Content

Home
Patient case
Patient case: Necrotizing Soft Tissue Infection

Patient case: Necrotizing Soft Tissue Infection

Discussion

A 55-year-old man with a history of type 2 diabetes mellitus and hypertension presents to the emergency department with severe pain and swelling in his left leg. He reports that two days ago, he noticed a small cut on his shin after accidentally bumping into a piece of furniture. Over the past 24 hours, the area has become increasingly swollen, red, and extremely painful, with dark discoloration spreading rapidly. He also complains of fever, chills, and confusion.

On examination, his temperature is 39.0°C (102.2°F), blood pressure is 88/55 mmHg, heart rate is 125 beats per minute, and respiratory rate is 24 breaths per minute. The affected leg appears swollen, erythematous, and tense, with areas of black necrosis and bullae formation. Crepitus is noted on palpation. Laboratory tests reveal leukocytosis, metabolic acidosis, and elevated creatinine.

An urgent surgical consultation is obtained, and bedside ultrasound shows gas in the soft tissues. The patient is immediately started on broad-spectrum intravenous antibiotics, aggressive fluid resuscitation, and vasopressor support. He is taken to the operating room for emergency debridement, where extensive necrotic tissue is removed. Cultures confirm a polymicrobial infection, including Streptococcus pyogenes and Clostridium perfringens.

Despite intensive treatment, the patient requires multiple debridements, followed by skin grafting. After several weeks of hospital care and rehabilitation, he recovers but requires long-term wound care.

Questions
1. What is the most likely diagnosis in this patient?

a) Cellulitis

b) Necrotizing soft tissue infection (NSTI)

c) Deep vein thrombosis

d) Erysipelas

2. Which clinical finding is most suggestive of necrotizing soft tissue infection?

a) Localized erythema with mild pain

b) Rapidly spreading skin discoloration with crepitus and bullae

c) Well-defined, raised borders of redness

d) Pain that improves with elevation of the limb

3. What is the most crucial aspect of treatment for necrotizing soft tissue infections?

a) Intravenous antibiotics alone

b) Surgical debridement and broad-spectrum antibiotics

c) Pain management and topical wound care

d) High-dose corticosteroids

4. Which risk factor likely contributed to this patient’s severe infection?

a) Recent travel history

b) Type 2 diabetes mellitus

c) High physical activity level

d) Prior history of mild allergies

Reveal answers

Answers

1. Answer: b) Necrotizing soft tissue infection (NSTI)

The rapid progression of pain, swelling, skin necrosis, and systemic symptoms (fever, hypotension) strongly suggests NSTI, a life-threatening condition requiring urgent intervention.

2. Answer: b) Rapidly spreading skin discoloration with crepitus and bullae

NSTI is characterized by rapidly worsening soft tissue necrosis, gas formation (crepitus), severe pain, and systemic toxicity. These features distinguish it from milder infections like cellulitis.

3. Answer: b) Surgical debridement and broad-spectrum antibiotics

Immediate surgical removal of necrotic tissue is critical to controlling infection. Antibiotics alone are insufficient due to rapid tissue destruction and bacterial toxin production.

4. Answer: b) Type 2 diabetes mellitus

Diabetes increases the risk of severe infections due to impaired immune function, poor circulation, and delayed wound healing, making minor skin injuries more likely to progress to NSTI.