Necrotizing soft tissue infections: Difference between revisions

Latest revision as of 19:22, 21 May 2025

Background

Abbreviation: NSTI
Includes necrotizing forms of cellulitis, myositis, and fasciitis

General types

Type 1: polymicrobial infection
Type 2: group A strep
- May occur in healthy individuals
- May occur via hematogenous spread from throat to site of blunt trauma

NSTI Types

Clinical Features

Nectrotizing fasciitis

Differential Diagnosis

Skin and Soft Tissue Infection

Look-A-Likes

Sporotrichosis
Osteomyelitis
Deep venous thrombosis
Pyomyositis
Purple glove syndrome
Tuberculosis (tuberculous inflammation of the skin)

Necrotizing rashes

Evaluation and Management

See specific type:

NSTI Types

External Links

MDCalc - LRINEC Score

References

Authors:

@@ Line 1: / Line 1: @@
-FASCIITIS
+==Background==
+*Abbreviation: NSTI
+*Includes necrotizing forms of cellulitis, myositis, and fasciitis
-- does not involve muscle- but can spread to muscle
+===General types===
+*Type 1: polymicrobial infection
+*Type 2: [[group A strep]]
+**May occur in healthy individuals
+**May occur via hematogenous spread from throat to site of blunt trauma
-- syst toxicity
+{{NSTI types}}
-- skin c blebs, crepitus, necrosis
+==Clinical Features==
+[[File:NectrotizingFasciitis.jpeg|thumb|Nectrotizing fasciitis]]
-- risks- dm, pvd, trauma or recent surg
+==Differential Diagnosis==
+{{SSTI DDX}}
+{{Necrotizing Rashes DDX}}
-- pain varies since nerve endings damaged- cessation or absence of pain may indicate worsening sxs
+==Evaluation and Management==
+See specific type:
-- necrosis of fat can lead to soapanification and hypocalemia
+{{NSTI types}}
-- pcn/gent/clinda
-MYOSITIS
-- myonecrosis- deep soft- tissue infection with  death of muscle
-- often with little skin changes but does have gas  formation
-- result of trauma or surgical wounds
--exotoxin of clostridia damages and kills muscle,  setting up anaerobic environment that promotes further bacterial growth
-- odor described as "sickly sweet:
-- pt usually anuric
-- muscle appears cooked or dead, does not bleed  when cut or retract when pinched
-NECROTIZTNG FASCIITIS
-- can occur p minor trauma
-- mortality 20- 50%
-Microorganisms
-- Type I Polymicrobrial- Anaerboic (mixed) staph, proteus, pseudomonas
-- Type 2 Streptococcal (toxin-generating)
-- Type 3 (?) Clostridium (gas gangrene)
-- Grp A beta hemolytic strep pyogenes releases substance in cell wall that causes separation of the dermal connective tissue resulting in continued inflammation and necrosis
-Signs/Symptoms
-"Hard Signs"
-- Hypotension
-- Gas on XR
-- Skin necrosis
-- Bullae
-- Crepitance
-Other common signs/symptoms
-- Systemic toxicity
-- Numbness or deep pain out of proportion to exam
-- Violaceous or hemorrhagic appearance
-- Pain beyond margins of cellulitis
-- Skip lesions
-Other
-- Meleney's synergistic gangrene- (progressive bacterial synergistic gangrene) involves superficial and deep fascial planes with thrombosis of subQ vessels and gangrene of tissue
-- Clostridial cellulitis- healthy muscle not invovled
-_ Fournier's syndrome- necrotizing subq infection of perineum- risk factors include infection or trauma to the perineal area,, anal intercourse, scratches, chemical or thermal burns or diabetes.  Obliteration of small branches of pudendal arteries results in dermal gangrene of perineal and scrotal skin.
-Labs
-Hyponatremia, Na<135
-Leukocytosis
-Imaging
-XR- gas
-CT- most commonly used, up to 80% sensitive
-UTZ- operator dependent
-MRI- overly sensitive
-Management
-- wide surgical debridement and excision
-- IV ABX
-- Resuscitate as in sepsis
-Unclear benefit
-- hyperbaric O2
-- IVIG
-Antibiotic Regimens
-Harbor:
-- community-acquired- Ceftriaxone/vanc/clinda +/- gent
-- hospital-acquired- Zosyn/vanc/clinda
-- pcn allergic- Cipro/vanc/clinda/gent
-Other common regimens:
-- pen/ ox/ gent/ clinda- and also use vanco
-/06 PANI
+==See Also==
+*[[Necrotizing rashes]]
+==External Links==
+*[http://www.mdcalc.com/lrinec-score-for-necrotizing-soft-tissue-infection/ MDCalc - LRINEC Score]
+==References==
+<references/>
 [[Category:ID]]