A Wolf in Cellulitis’ Clothing: Managing Necrotizing Fasciitis

-Case-

It’s a busy shift in the ED when EMS rolls in with a 56-year-old man. He’s diaphoretic, tachycardic, and complaining of excruciating pain in his left leg. His wife says it started as a minor scrape two days ago, but now his entire leg is swollen, red, and dusky. His vitals are notable for a fever to 103°F, heart rate of 130, and blood pressure at 90/60. As you peel back the bandage on his leg, you notice a foul smell and his skin gives way with gentle palpation.

When dealing with skin infections that present with systemic symptoms, your suspicion for more concerning infections should be very high. In this case, the presence of hypotension and a foul odor further suggest deep tissue involvement and impending septic shock.

-Evaluation-

Necrotizing fasciitis is a rapidly progressing, life-threatening soft tissue infection that demands early recognition and aggressive management.

The classic presentation includes rapidly worsening pain out of proportion to exam findings, swelling, erythema, and crepitus (though this is often a later finding). Systemic signs such as fever, tachycardia, and hypotension should raise immediate concern. Patients may also develop bullae, skin discoloration, or necrosis as the infection spreads.

Risk factors for necrotizing skin infections include diabetes, immunosuppression, recent trauma or surgery, IV drug use, and peripheral vascular disease. While Group A Strep is the most common culprit, polymicrobial infections (including anaerobes and gram-negative organisms) are also common.

Diagnosis is clinical, but imaging can support suspicion. A CT with IV contrast of the affected body part can show fascial thickening, gas formation, and fluid collections; however, waiting for imaging should never delay surgical intervention! Lab findings often include an elevated WBC, metabolic acidosis, and an elevated creatine kinase (suggesting muscle involvement). One handy clinical decision-making tool, the LRINEC score, can help stratify risk but should not replace clinical judgment.

-Management-

For these infections, time is tissue. The cornerstone of treatment is early surgical debridement – this is a surgical emergency, not a “wait and see” diagnosis. As such, when the alarm bells are ringing for a possible necrotizing skin infection, call that surgery consult ASAP!

In addition, broad-spectrum IV antibiotics should be initiated immediately, typically including vancomycin (for MRSA coverage), zosyn (for gram-negative and anaerobic coverage), and clindamycin (to suppress toxin production by GAS). Hemodynamic support with IV fluids and vasopressors is often needed due to hypotension/septic shock.

-Fast Facts-

• When prompted with a skin infection, crepitus, bullae, necrosis, and hypotension are key for a necrotizing infection – these are all red flags
• Clinical suspicion is key; imaging can help but never delay surgery for a scan!
• Emergent surgical debridement, broad-spectrum antibiotics, and aggressive supportive care are the mainstays of treatment
• If you’re debating whether to call surgery, you’ve already waited too long!

Necrotizing fasciitis spreads fast, kills tissue, and turns stable patients into crashing ones in hours. Hesitation can be deadly; when the exam and vitals don’t match, when pain is excruciating, and when the skin changes are rapid, trust your gut, call surgery, and act fast. Lives (and limbs) depend on it!

Want to read more about this topic? Click ✨here✨to read our in-depth study guide!

Cheers,

Tamir Zitelny, MD