Skin_and_Soft_Tissue _Infections

Skin and Soft Tissue Infections : 

Skin and Soft Tissue Infections R. Pepe M.D.

Introduction : 

Introduction Inpatient conditions Outpatient Skin findings associated with systemic infections

Classification of skin infections : 

Classification of skin infections Primary pyodermas: impetigo, folliculitis, ecthyma, erysipelas, cellulitis Infectious gangrene and gangrenous cellulitis Erythrasma Nodular lesions Hyperplastic Vascular papules ECM Cutaneous involvement in systemic infections

Cellulitis : 

Cellulitis Acute spreading infection of the skin and involves subcutaneous tissues. Group A Strep and Staph. aureus most common pathogens Occurs via skin breaks; pain, tenderness develops over a few days, fever and systemic findings, elevated wbc common. Regional lymphadenopathy common, bacteremia up to 5%. Superinfection with gram – can occur

Cellulitis : 

Cellulitis Repeated episodes common in patients with LE edema, after CABG venous harvest Multiple pathogens isolated from debridement in diabetic patients Dx: 1)culture any open wound, aspirate bullae, ?edge 2)BC 3)cx and path punch biopsy

Cellulitis : 

Cellulitis Rx: Staph. active PCN or cephalosporin, or based on culture, ?empiric rx for MRSA Outpatient or inpatient management? Prevention of recurrent episodes

Erysipelas : 

Erysipelas Distinctive type of superficial cellulitis with prominent lymphatic involvement, sharply demarcated borders Group A Strep, other Strep sp. Rx: PCN

Processes to be distinguished from cellulitis : 

Processes to be distinguished from cellulitis Infections: Necrotizing fasciitis (types I and II) Anaerobic myonecrosis (gas gangrene) Cutaneous anthrax with prominent edema Prominent response to vaccinia vaccination ECM

Processes to be distinguished from cellulitis : 

Processes to be distinguished from cellulitis Non-infectious: Insect bite Fixed drug reaction Acute gout DVT FMF-associated cellulitis-like erythema Pyoderma gangrenosa Sweet’s syndrome Kawasaki disease Well’s syndrome (eosinophilic cellulitis) Carcinoma erysipeloides

Other pathogens : 

Other pathogens Erysipelothrix rhusiopathiae (handling shellfish) Aeromonas ( water exposure) Vibrio vulnificus, other vibrio (water exposure or seafood, liver disease) Fungus/molds: immunocompromised

Erisypeloid : 

Erisypeloid

Vibrio vulnificus : 

Vibrio vulnificus

Aeromonas : 

Aeromonas

Fusaria : 

Fusaria

Infectious Gangrene : 

Infectious Gangrene Rapidly progressing cellulitis with extensive necrosis of subQ tissues and overlying skin Specific clinical entities depending on pathogen and anatomic location: necrotizing fasciitis (group A strep or mixed), gas gangrene (Clostridia), progressive bacterial synergistic gangrene (post op wounds), synergistic necrotizing cellulitis: gangrenous cellulitis in immunocompromised (Mucor) Rx: Surgery + appropriate antibiotics

Necrotizing fasciitis : 

Necrotizing fasciitis

Necrotizing fasciitis : 

Necrotizing fasciitis

Necrotizing fasciitis : 

Necrotizing fasciitis Pain is a prominent symptom, marked systemic toxicity, rapid progression, fever, crepitus can be present, foul smelling “dishwater” drainage Type I: mixed pathogens including 1 anaerobe, diabetes Type II: Strep group A (“flesh eating bacteria”) Surgery determines outcome

Group A Strep : 

Group A Strep Toxin producing strains Can cause infections of various depth with systemic symptoms, sepsis, high mortality if inadequate surgery Rx: IV PCN + Clinda + IVIG (Empiric abx before cx will be broader)

Other subcutaneous tissue infections : 

Other subcutaneous tissue infections Clostridial anaerobic cellulitis Gas gangrene (involves muscle) Fournier’s gangrene (perineal area) Synergistic necrotizing cellulitis

Clostridia : 

Clostridia Anaerobic cellulitis > gas gangrene, complications of trauma, post op wounds, combat Pain is not prominent in cellulitis, systemic toxicity is not pronounced, thick foul smelling drainage, + crepitus Usually C. perfringens, possibly C. septicum (with bacteremia) C. sordelli has occurred with contaminated drug materials (black tar heroin)

Clostridia – Gas gangrene : 

Clostridia – Gas gangrene Involves muscle Rapidly progressive, life threatening, associated with systemic toxicity. Pain is a prominent symptom, with fever (hypothermia late). Adjacent skin may be white early then takes on a characteristic bronze. Discharge can have gas bubbles Rx: surgery, PCN G + clinda + GN agent if seen in gram stain

Gas gangrene : 

Gas gangrene

Gas gangrene : 

Gas gangrene

Gas gangrene : 

Gas gangrene

Pyomyositis : 

Pyomyositis Acute bacterial infection of skeletal muscle, usually caused by Staph. aureus No predisposing penetrating wound, vascular insufficiency, or contiguous infection Most cases occur in the tropics 60% of cases outside of tropics have predisposing RF: DM, EtOH liver disease, steroid rx, HIV, hematologic malignancy

Pyomyositis : 

Pyomyositis Hx of blunt trauma or vigorous exercise (50%), then period of swelling without pain. 10-21 days later, pain, tenderness, swelling and fever, Pus can be aspirated from muscle. 3rd stage: sepsis, later metastatic abscesses if untreated Dx: X-ray, US, MRI or CT Rx: surgical drainage +abx

Pyomyositis with toxic shock : 

Pyomyositis with toxic shock Group A strep Presentation of more fulminant disease, compartment syndrome common, no hx pharyngitis or tonsillitis. Increased CPK common Rx: surgery PCN + clinda+ IVIG

Abscesses : 

Abscesses Occur at sites of trauma, injection sites Staph. aureus. CA-MRSA has become very common All abscesses need culture; or empiric rx for CA-MRSA

Impetigo : 

Impetigo Crusted, superficial skin lesions. Group A strep or Staph. Young children, crowding

Other Staph. skin infections : 

Other Staph. skin infections Impetigo ( also group A strep) Bullous impetigo SSSS (exfoliative toxin) Folliculitis – involves hair follicles (Other pathogens: Pseudomonas, Candida, Malassezia furfur in specific settings) Furuncles and carbuncles

Impetigo : 

Impetigo

SSSS : 

SSSS

Folliculitis (MRSA) : 

Folliculitis (MRSA)

Folliculitis (Pseudomonas) : 

Folliculitis (Pseudomonas)

Furuncle : 

Furuncle

Carbuncle : 

Carbuncle

Ecthyma : 

Ecthyma Primary: extension of impetigo through epidermis, “punched out” lesions on LE common Can occur as manifestation of bacteremia

Ecthyma : 

Ecthyma

ECM : 

ECM

ECM : 

ECM

Erythrasma : 

Erythrasma

Erythrasma : 

Erythrasma

Nodular lesions : 

Nodular lesions Sporotrichosis, other fungal infections

Sporotrichosis : 

Sporotrichosis

Anthrax : 

Anthrax Cutaneous lesion, after an abrasion from animal product Painless papule, enlarges, significant edema. Low grade fever. Eschar may form. Regional LN common. Bacteremic dissemination can occur if untreated, meningitis may occur as a complication Rx: avoid debridement, punch bx after starting empiric abx

Anthrax : 

Anthrax

Skin manifestations in bacteremias : 

Skin manifestations in bacteremias

Ecthyma : 

Ecthyma

Endocarditis : 

Endocarditis

Meningococcemia : 

Meningococcemia