Wet gangrene

Background

Gangrene General Info

• A form of tissue necrosis characterized by critically insufficient blood supply leading to tissue death.
• Primarily divided into wet gangrene vs dry gangrene. Other, specific forms of gangrene include Fournier's gangrene, gas gangrene, and necrotizing fasciitis.
• Most commonly occur in distal extremities, clasically the feet.
• Main risk factors are diabetes, smoking, and peripheral arterial disease.

Clinical Features

• Usually due to peripheral arterial or venous disease, but can also be sequelae of trauma or burns causing vascular injuries.
• Presents with swollen, pale, soft tissue, often with a putrid smell and purulent discharge.
• As tissue is infected, wet gangrene presents a higher risk of systemic infection than dry gangrene.

Differential Diagnosis

Foot infection

Skin and Soft Tissue

• Cellulitis
• Erysipelas
• Abscess
• Puncture wound infection
• Paronychia
• Ingrown toenail (infected)
• Tinea pedis
• Infected wound / diabetic foot ulcer

Deep Tissue / Limb-Threatening

• Necrotizing soft tissue infections
  • Necrotizing fasciitis
  • Necrotizing myositis
  • Necrotizing cellulitis
• Gangrene
  • Dry gangrene
  • Wet gangrene
  • Gas gangrene
• Diabetic foot infection
• Trench foot

Bone and Joint

• Osteomyelitis
• Septic arthritis
• Septic bursitis

Look A-Likes

• Gout
• Pseudogout
• Charcot foot
• Peripheral artery disease
• Deep venous thrombosis
• Venous stasis dermatitis
• Sporotrichosis
• Contact dermatitis
• Calciphylaxis
• Lymphedema
• Erythema nodosum
• Stress fracture
• Reactive arthritis

Evaluation

Workup

• CBC
• Chemistry
• Consider:
  • X-ray
  • blood cultures
  • lactate

Diagnosis

• History and physical examination are usually sufficient to make the diagnosis.
• Given higher risk for systemic infection, patients should be evaluated for signs/symptoms of sepsis

Management

• Wet gangrene requires broad spectrum antibiotic coverage, as these are often polymycrobial infections.
• Requires surgical consultation as rapid debridement or amputation of necrotic tissue is required to prevent further spread of infection.

Antibiotics

Coverage	Drugs
Broad-spectrum (typical start)	Piperacillin-tazobactam OR meropenem OR cefepime + metronidazole
MRSA	Add vancomycin or linezolid
Anaerobic/gas gangrene	Penicillin G + clindamycin
Polymicrobial (common in diabetics)	Carbapenem monotherapy or combo therapy (e.g., ceftriaxone + metronidazole + vancomycin)

Disposition

• Admission

See Also

• Gangrene