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

Dry gangrene of toe.

Dry gangrene of fingertips.

Dry gangrene of foot.

Dry gangrene of foot.

• Dry gangrene is tissue necrosis often due to chronic progressive ischemia from peripheral arterial disease, but can also be caused by acute limb ischemia.
• Presents with dry, cold, shrunken tissue, usually ranging from dark red to completely black, often with a clear line of demarcation between healthy and necrotic tissue.
  • Usually not associated with infection (in contrast to Wet gangrene) as bacteria cannot survive in the dry/mummified tissue; however, development of secondary infection is possible
• Typically not painful due to associated nerve death
• Nonpalpable pulses are common

Differential Diagnosis

Foot infection

• Gout
• PsuedoGout
• Cellulitis
• Gangrene
  • Dry gangrene
  • Wet gangrene
• Trench foot
• Abscess
• Necrotizing soft tissue infections
  • Necrotizing fasciitis
  • Necrotizing myositis
  • Necrotizing cellulitis
• Osteomyelitis
• Diabetic foot infection
• Charcot Foot

Look A-Likes

• Peripheral artery disease
• Sporotrichosis
• Deep venous thrombosis

Evaluation

• History and physical examination are usually sufficient to make the diagnosis.
• Consider ABI or pulse volume recording (PVR) for early evaluation of peripheral arterial disease.
• If acute limb ischemia is suspected, consider a CTA of the affected limb and a vascular surgery consultation.

Management

• Infection rarely present
  • <8% of cases convert to wet gangrene
  • If has any areas consistent with wet gangrene or surrounding SSTI or Necrotizing fasciitis, treat as for those entities
  • Keep area clean and dry to prevent infection; consider debridement
• Early involvement of vascular surgery
  • Although revascularization is possible for chronic ischemia, dry gangrene signifies that the tissue is already necrotic
  • Amputation is often the treatment of choice for significant necrosis; patients could also await autoamputation, which usually occurs in <6mo
  • 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.
• Ensure patient has adequate medical management of predisposing risk factors

Disposition

• Outpatient, if acute limb ischemia is NOT a concern

See Also

• Wet gangrene