What is the Difference Between Dry and Wet Gangrene

The main difference between dry and wet gangrene is that dry gangrene results from the reduction or blockage of arterial blood flow due to diabetes, arteriosclerosis, trauma, frostbite, injury or tobacco addiction, but wet gangrene mainly results from venous obstruction associated with infections. Furthermore, dry gangrene is comparatively not dangerous, while wet gangrene is dangerous as it develops sepsis and causes death in a few days. 

In brief, dry and wet gangrene are two types of gangrene, a type of tissue death caused by the lack of blood supply. Significantly, the common symptoms of them include a change in skin color to red or black, numbness, swelling, pain, skin breakdown, and coolness.  

Key Areas Covered 

1. What is a Gangrene
     – Definition, Causes, Symptoms
2. What is Dry Gangrene
     – Definition, Significance
3. What is Wet Gangrene
     – Definition, Significance
4. What are the Similarities Between Dry and Wet Gangrene
     – Outline of Common Features
5. What is the Difference Between Dry and Wet Gangrene
     – Comparison of Key Differences

Key Terms 

Dry Gangrene, Gangrene, Swelling, Tissue Death, Wet Gangrene

What is a Gangrene 

Gangrene is a dangerous and potentially fatal condition caused by the lack of blood flow to a large area of tissue. Hence, this results in the breakdown of the tissue and eventual death. Although it is common in toes, fingers, legs, and hands, located away from the heart, gangrene can also occur in internal organs. When left untreated, gangrene can spread through the body, leading to go to shock, which can be life-threatening. 

Furthermore, the history of certain medical conditions including infections, trauma, poor wound healing, and diseases such as atherosclerosis in legs and arms, diabetes, Raynaud’s disease, appendicitis, hernia, etc. may lead to gangrene. Typically, one can merely recognize gangrene from the color changes in a local area; that is, into red, blue or black, and becomes numb or painful.

Besides, there are several types of gangrene; dry gangrene, wet gangrene, gas gangrene, Fournier’s gangrene, etc. Of these, the dry and wet gangrene are described in the below sections. Of these, gas gangrene occurs as a result of the accumulation of gas produced by a bacterial infection. Also, it causes severe pain, fever, and the skin will crackle like bubble wrap when pressed. On the other hand, Fournier’s gangrene affects genitals and groin. Additionally, it affects internal organs such as intestines and gallbladder. Importantly, patients with this type of gangrene can be very sick typically be very sick with fever, low blood pressure, and severe pain.  

What is Dry Gangrene 

Dry gangrene is a type of gangrene with local tissue death with the tissue eventually being sloughed off. Significantly, the main causes of dry gangrene include diabetes, atherosclerosis, and tobacco smoking, which lead to arterial occlusion. As it often produces cool, dry, and discolored appendages (sometimes termed “mummified”) with no oozing fluid or pus, it is named as dry gangrene. Usually, surgery can remove the dry gangrene along with a course of antibiotics and anticoagulants.

Figure 2: Dry Gangrene

What is Wet Gangrene  

Wet gangrene is another type of gangrene, being the most dangerous type due to the development of sepsis and eventual death within a few days. Here, a bacterial infection results in the venous obstruction, producing tissue swelling and the production of gas and bacterial toxins in tissues. It often produces an oozing fluid or pus, and hence, the term “wet.” Also, the symptoms of the early stages of a wet gangrene include arching pain with swelling, the development of reddish color or blanched appearance, coolness, ulceration, and crackly sensation. Importantly, wet gangrene requires immediate treatment and hospitalization, following the local area debridement. 

Similarities Between Dry and Wet Gangrene  

• Dry and wet Gangrene are two types of gangrene, which occur as a result of lack of blood supply.  
• Both are types of tissue death of arms and legs.  
• Their main symptoms include change in skin color to red or black, numbness, swelling, pain, skin breakdown, and coolness.    
• Surgery,  medical treatment, supportive care, and occasionally, rehabilitation are the main forms of treatment for both types of gangrene. 

Difference Between Dry and Wet Gangrene 

Definition 

Dry Gangrene refers to a type of gangrene, which develops in the presence of arterial obstruction, producing sharply localized dryness of the dead tissue. Meanwhile, wet gangrene refers to the type of gangrene caused by a bacterial infection in the affected tissue. 

Mechanism 

Arterial occlusion is the main mechanism of dry gangrene, while venous obstruction is the mechanism of wet gangrene. 

Characterization 

The characteristics of dry gangrene include dryness, shrinkage, and the black color of the dead tissue, sharply demarcated from adjacent tissue by a line of inflammation. On the other hand, the characteristics of wet gangrene include softening, swelling, blistering, rotten, wet, and dark appearance. 

Putrefaction 

Putrefaction is limited in dry gangrene due to very little blood supply, but putrefaction is marked in wet gangrene due to the congestion of organs with blood. 

Line of Demarcation 

A line of demarcation is present at the junction between healthy and gangrenous parts in dry gangrene, but there is no clear cut line between the healthy and gangrenous parts in wet gangrene. 

Survival of Bacteria 

Bacteria fail to survive in dry gangrene, but in contrast, numerous bacteria are present in wet gangrene. 

Treatment 

Dry gangrene can be treated with surgery, and wet gangrene requires immediate treatment as it can cause death in a few days. 

Prognosis 

Prognosis is better in dry gangrene due to little septicemia, but the prognosis is poor in wet gangrene due to profound toxemia. 

Conclusion 

Dry gangrene is a type of gangrene, mainly occurring in limbs. Generally, the common cause of dry gangrene is arterial occlusion. Also, the characteristics of this type of gangrene include the dryness, shrinkage, and black color of the dead tissue. Besides, dry gangrene is sharply demarcated by a line of inflammation, separating the healthy tissue. Therefore, the prognosis of dry gangrene is better. Meanwhile, wet gangrene is another type of gangrene, mainly occurring due to bacterial infection, which ultimately leads to venous obstruction. Furthermore, its characteristics include softening, swelling, rotten, and dark appearance. Also, a bacterial infection is the main distinguishing feature. Hence, prognosis of wet gangrene is poor. Thus, in summary, the main difference between dry and wet gangrene is the mechanism of occurrence and characteristics. 

References:

1. Davis, Charles Patrick. “Gangrene Infection Causes, Symptoms, Treatment, Wet vs. Dry.” MedicineNet, MedicineNet, 17 Jan. 2020, Available Here.

Image Courtesy:

1. “Plate II Mortification (gangrene), Robert Carswell 1830s Wellcome L0074380” By wellcomeimages.org(CC BY 4.0) via Commons Wikimedia  
2. “Dry gangrene of the foot and ankle Wellcome L0061216” By wellcomeimages.org(CC BY 4.0) via Commons Wikimedia