Approach to evaluation and initial management of possible necrotizing soft tissue infection

NSTI: necrotizing soft tissue infection; MRI: magnetic resonance imaging.
* Refer to UpToDate text for discussion of approach to empiric antimicrobial therapy. Supportive management may require fluid resuscitation, hemodynamic support, and management of comorbid conditions. Supportive management is adjusted according to clinical features over time.
¶ Intraoperative findings include extensive soft tissue destruction with fascia that is not adherent to adjoining layers. Soft tissue involvement often extends beyond margins based solely on external appearance. Thrombosis of the underlying dermal capillary network is apparent and precedes overt skin necrosis; incision through involved areas will not bleed normally.
Δ Decisions regarding whether to pursue surgical intervention and the appropriate timeframe should be tailored to individual clinical circumstances, with consideration of patient's immune status and other comorbidities.
◊ The first-line imaging study depends on the anatomic location, clinical condition of the patient, availability of technology, and expertise at interpretation. Other imaging modalities include MRI and ultrasound.
§ Imaging findings of NSTI include gas in the soft tissues, fluid collections, absence or heterogeneity of tissue enhancement with intravenous contrast, and inflammatory changes beneath the fascia.
¥ Alternative diagnoses include other soft tissue infections (including cellulitis or abscess) and inflammatory skin conditions. Refer to the UpToDate text for further discussion.
‡ If clinical concern for NSTI persists, MRI or limited surgical exploration with fascial biopsy may be pursued.