Dry 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 disease, but can also be caused by acute limb ischemia.
• Presents with dry, shrunken tissue, usually ranging from dark red to completely black, often with a clear line of demarcation between healthy and necrotic tissue.
• Typically not painful.

Differential Diagnosis

Foot infection

• Cellulitis
• Gangrene
  • Dry gangrene
  • Wet gangrene
• Trench foot
• Abscess
• Necrotizing soft tissue infections
  • Necrotizing fasciitis
  • Necrotizing myositis
  • Necrotizing cellulitis
• Osteomyelitis
• Diabetic foot infection
• Wet-sock erosions

Look A-Likes

• Ingrown toenail
• Peripheral artery disease
• Sporotrichosis
• Deep venous thrombosis

Evaluation

• History and physical examination are usually sufficient to make the diagnosis.
• If acute limb ischemia is suspected, consider a CTA of the affected limb and a vascular surgery consultation.

Management

• Infection rarely present; approximately 7.7% of cases convert to wet gangrene
• Keep area clean and dry to prevent infection; consider debridement
• Will usually auto-amputate in <6mo
• Refer to vascular surgery in case fails to auto-amputate; may benefit from revascularization therapy to prevent further tissue death. Diabetes or immunocompromise may warrant lower threshold for consultation
• If acute limb ischemia is present, embolectomy or surgical bypass may be required to restore flow.

Disposition

• Outpatient, if acute limb ischemia is NOT a concern

See Also

• Gangrene