Common Associated Sign of Necrotizing Fasciitis
The correct answer is C. Edema - edema extending beyond the area of cutaneous erythema is a common and diagnostically important sign of necrotizing fasciitis that helps distinguish it from superficial cellulitis.
Clinical Presentation and Key Distinguishing Features
Edema is present in approximately 80% of necrotizing fasciitis cases and represents a critical diagnostic feature 1. More specifically, edema or tenderness extending beyond the cutaneous erythema is one of the cardinal signs that suggests deeper tissue involvement 1.
Why Edema is the Most Characteristic Sign
The other options, while present in necrotizing fasciitis, are less specific:
- Redness (erythema) occurs in 90% of cases but is also common in simple cellulitis, making it less diagnostically useful 1
- Hotness is a general inflammatory sign present in many superficial infections
- Low amount of grey stain discharge is actually a surgical finding seen during operative exploration, not a common presenting clinical sign 1
Critical Diagnostic Features Beyond Edema
The most important clinical features that should raise suspicion for necrotizing fasciitis include 1:
- Severe pain disproportionate to clinical findings - the hallmark early symptom
- Wooden-hard feel of subcutaneous tissue extending beyond apparent skin involvement - this distinguishes fasciitis from cellulitis where tissues remain palpable and yielding 1
- Systemic toxicity with altered mental status
- Failure to respond to initial antibiotic therapy
- Skin necrosis, ecchymoses, or bullous lesions (70% of cases) 1
- Crepitus indicating gas in tissues 1
Common Pitfall
The paucity of cutaneous findings early in the disease makes diagnosis difficult - only 13 of 89 patients (15%) in one series had necrotizing fasciitis diagnosed at admission 2. Clinical judgment and high index of suspicion remain paramount 1, 3. Do not wait for imaging studies if clinical suspicion is high, as this delays definitive surgical treatment 1.