What is dry gangrene?

Dry Gangrene: Clinical Description

Dry gangrene is tissue death (necrosis) caused by chronic ischemia, characterized by tissue that becomes numb, dry, wrinkled, and dead, with a clear line of demarcation between viable and necrotic tissue. 1

Pathophysiology

• Dry gangrene occurs due to reduced blood supply in body tissues leading to necrosis, most commonly arising from chronic ischemia rather than infection 2, 1
• The tissue becomes progressively ischemic, resulting in cellular death without the presence of bacterial infection that characterizes wet gangrene 2
• In diabetic patients, this is often secondary to larger-vessel atherosclerosis rather than "small-vessel disease" 3

Clinical Characteristics

Key distinguishing features of dry gangrene include:

• Appearance: The affected tissue becomes numb, dry, wrinkled, and dead with a characteristic mummified appearance 1
• Color changes: Tissue typically progresses from initial pallor to bronze discoloration, then to black, demarcated necrotic tissue 2, 4
• Demarcation: A clear line of demarcation develops between viable and necrotic tissue, which is the hallmark feature distinguishing it from wet gangrene 2, 1
• Texture: The tissue is cold, dry, and hard rather than moist or purulent 4
• Location: Most commonly affects the extremities, particularly toes and fingers in diabetic patients 2, 1

Clinical Presentation Specifics

• The affected area lacks signs of active infection such as purulence, foul odor, or spreading erythema 3
• Peripheral pulses may be absent or diminished in the affected limb due to underlying vascular disease 4, 5
• The tissue becomes progressively darker and more desiccated over time 4
• Pain may be present initially but often diminishes as tissue becomes completely necrotic and numb 1

Important Clinical Distinctions

Dry gangrene differs fundamentally from wet gangrene and gas gangrene:

• Unlike wet gangrene, dry gangrene lacks bacterial infection, purulent drainage, and systemic toxicity 2
• Unlike gas gangrene, there is no crepitus, no gas in tissues, and no rapid progression with systemic toxicity 3, 6
• The presence of clear demarcation in dry gangrene allows for potential conservative management in select cases, whereas wet and gas gangrene require urgent surgical intervention 3, 2

Management Implications

• When all or part of a foot has dry gangrene, it may be preferable (especially for patients who are poor surgical candidates) to allow necrotic portions to auto-amputate 3
• Adherent eschar may be left in place, especially on the heel, until it softens enough to be more easily removed, provided there is no underlying focus of infection 3
• However, recent evidence suggests that waiting for autoamputation may lead to worse clinical outcomes, and early surgical intervention should be considered to improve quality of life 1

Common Pitfalls

• Do not confuse dry gangrene with early wet gangrene or necrotizing infection—the absence of infection, clear demarcation, and dry appearance are critical distinguishing features 3, 2
• If clinical findings worsen or signs of infection develop, surgical intervention becomes necessary regardless of initial appearance 3
• Patients with dry gangrene and critical ischemia should be referred to vascular surgery for potential revascularization 3