Wet gangrene: causes, symptoms and treatment

Wet gangrene is tissue death accompanied by bacterial infection. The tissues become swollen and moist, and blisters and foul-smelling discharge may appear. Unlike the "dry" form, in which necrotic areas "mummify" due to prolonged ischemia, wet gangrene progresses rapidly and is almost always accompanied by a pronounced inflammatory response. This is a life-threatening condition that can progress to sepsis and shock. [1]

Wet gangrene most often develops on the feet and shins, especially in people with diabetes and arterial blood flow problems. However, it can also occur in other areas: on the hands, in the perineum (the classic variant is Fournier's gangrene), and after injuries, surgeries, and injections. The general principle is the same: there is an entry point for infection, plus poor blood supply, which interferes with the immune response and the delivery of antibiotics to the site. [2]

Microorganisms associated with wet gangrene can vary widely. These are often "mixed" infections, where aerobic and anaerobic bacteria are present simultaneously. "Monoinfections" are also possible—for example, group A streptococci, methicillin-resistant Staphylococcus aureus, clostridia (in gas gangrene), and, if exposed to water, vibrios or aeromonas. The rate of development, toxicity, and choice of initial therapy depend on these factors. [3]

The bottom line: wet gangrene is a surgical and resuscitation emergency. Survival is determined by hours: the sooner intensive fluid therapy, broad-spectrum antibiotics, and surgical debridement or amputation of non-viable tissue are initiated, the better the prognosis. Any "confirmatory" tests are permissible only as long as they do not delay surgery. [4]

Terms and clinical classification

In practice, a distinction is made between "dry," "wet," and "gas" gangrene. "Gas" gangrene is essentially a clostridial myonecrotic infection with gas formation in the tissues. Necrotizing soft tissue infections are also distinguished separately: necrotizing fasciitis, myositis, and necrotizing cellulitis. These terms describe the depth of the lesion and the dynamics of its spread. [5]

Microbiologically, necrotizing infections are divided into types: Type I - polymicrobial (most common), Type II - monobacterial (usually group A streptococci, sometimes staphylococci), Type III - clostridial or "waterborne" pathogens (vibrios, aeromonads). This framework helps select initial antibiotics and consider specific tactics for waterborne injuries. [6]

Fournier's gangrene is a rapidly progressive necrotizing fasciitis of the perineum and external genitalia. It is usually polymicrobial and requires immediate surgical intervention, aggressive antibacterial therapy, and frequent repeat necrotomies followed by reconstruction. [7]

Table 1. Comparison of forms of gangrene

Sign	Dry	Wet	Gas
The main mechanism	Ischemia without active infection	Necrosis plus infection	Clostridial myonecrosis with gas formation
Clinic	Dry "mummified" tissue, clear border	Swelling, blisters, foul-smelling discharge, pain	Severe pain, crepitus, lightning-fast deterioration
Pace	Slow	Fast	Very fast
Tactics	Revascularization, planned necrectomy/amputation	Urgent surgery, antibiotics, intensive care	Immediate surgery, anti-anaerobic coating, intensive care
Risks	Autoamputation, chronicity	Sepsis, shock, loss of limb	Death within hours due to delayed treatment

Medical coding

Coding is important for routing, statistics, and payment of medical care. For wet gangrene and necrotizing infections, both "general" (unspecified gangrene) and "special" codes (necrotizing fasciitis, Fournier's gangrene, etc.) are used. [8]

Table 2. Selection of codes according to current versions of classifiers

Situation	ICD-10 (ICD-10-CM)	ICD-11 (ICD-11 MMS)
Gangrene, unspecified	I96; R02	MC85 "Gangrene"
Necrotizing fasciitis	M72.6	1B71.* (streptococcal, polymicrobial, unspecified, etc.)
Gangrene in diabetes mellitus	E10.52 / E11.52	Post-coordination: Diabetes code plus MC85
Atherosclerosis of the extremities with gangrene	I70.26 and others.	Post-coordination with vascular codes
Fournier's gangrene	N49.3 (for men); N76.82 (for women)	Necrotizing fasciitis code plus anatomical details

The scale of the problem: epidemiology and outcomes

Necrotizing soft tissue infections are rare but extremely dangerous. National databases estimate the incidence of necrotizing fasciitis to be approximately 0.3-15 cases per 100,000 population per year, with mortality rates ranging from 17% to 35%, and higher if treatment is delayed. In recent years, the number of deaths associated with necrotizing fasciitis has increased, which is attributed to the aging population and the increasing prevalence of diabetes. [9]

Fournier's gangrene is less common, but its progression is particularly rapid. Modern observational series show hospital mortality rates of approximately 11-20%, with women often having worse outcomes than men. Factors associated with poor outcomes include late admission, multidrug-resistant flora, and a high organ failure index at admission. [10]

Diabetes mellitus is a major risk factor. Approximately 50-60% of patients with diabetic foot ulcers develop infection, and 20% of moderate to severe infections result in amputation. Five-year mortality after amputation due to diabetic foot ulcers is comparable to that of cancer. [11]

Table 3. Key figures from recent surveys

Indicator	Range
Frequency of necrotizing fasciitis	0.3-15 per 100,000 per year
In-hospital mortality in necrotizing fasciitis	17-35%
The proportion of infected diabetic ulcers	50-60%
Risk of amputation in moderate to severe foot infections	≈20%
Mortality in Fournier's gangrene (modern series)	11-20%

Why does wet gangrene develop?

The breeding ground for wet gangrene is a combination of impaired blood flow and infection. Ischemia creates "oxygen starvation," reducing the delivery of immune cells and antibiotics, and providing bacteria with a favorable environment for proliferation. The inflammatory cascade leads to thrombosis of small vessels and further worsening necrosis—a vicious cycle. [12]

The microbiology is variable. Polymicrobial variants include enterobacteria, bacteroides, peptococci, and peptostreptococci, as well as staphylococci and streptococci. Monobacterial forms are most often associated with group A streptococci or vibrios during marine exposures. Clostridia produce gas and toxins, which explains the fulminant nature of gas gangrene. [13]

A separate scenario is "water-related" wounds: Vibrios are dangerous in saltwater injuries (especially in people with chronic liver disease), while aeromonas are dangerous in freshwater injuries. Special antibiotic regimens are needed here, and delay is especially dangerous: time is of the essence. [14]

Table 4. Common microbiological scenarios

Scenario	Possible pathogens	Clinical features
Polymicrobial infection	Enterobacteriaceae + anaerobes + staphylococci/streptococci	More common in diabetes, obesity, and the elderly
Monobacterial streptococcal	Group A streptococcus	Rapid spread, toxic shock
Clostridial	Clostridia	Gas in tissues, lightning-fast flow
Sea water	Vibrio vulnificus and others.	Blisters, hemorrhagic bullae, severe intoxication
Fresh water	Aeromonas	Often multi-resistant strains

Who is at risk?

Major risk factors include diabetes, peripheral arterial disease, smoking, obesity, old age, immunosuppression, alcoholism, chronic kidney disease, trauma, and surgery, especially in polluted conditions. The presence of a chronic foot ulcer dramatically increases the risk of infection and gangrene. [15]

Contact of a wound with water, especially warm seawater, as well as fish fin pricks and marine animal bites, pose a separate risk factor for aquatic pathogens. Risk factors for Fournier's gangrene in the perineal region include diabetes, obesity, perirectal abscesses, and urological interventions. [16]

Table 5. Risk factors and example situations

Factor	Examples
Metabolic	Diabetes mellitus, obesity
Vascular	Atherosclerosis of the arteries of the extremities, critical ischemia
Immune	Glucocorticoids, oncohematological diseases
Behavioral	Smoking, drinking alcohol
Expositions	Sea/fresh water, animal bites, injuries, surgeries

How to recognize: symptoms and red flags

Locally, increasing pain (often disproportionate to the wound's appearance), swelling, redness, and then blisters and areas of black or gray-green necrosis are observed. Discharge becomes foul-smelling, sometimes with a gas taint. With gas gangrene, crepitus may be felt upon palpation. [17]

Fever, weakness, tachycardia, nausea, a drop in blood pressure, and confusion develop rapidly. These are signs of developing sepsis and shock, requiring immediate emergency medical attention and hospitalization in a surgical ward. [18]

Table 6. Red flags and first action

Sign	What to do
Sharp pain "not consistent with the appearance" of the wound	Urgent evaluation by a surgeon
Rapidly growing swelling, blisters, black spots	Immediate hospitalization
Foul-smelling discharge, suspected gas in tissues	Without delay, to the operating room
Fever, severe weakness, drop in blood pressure	Sepsis treatment protocol (infusion, antibiotics, surgery)

Diagnostics: What's Really Important and in What Order

First and foremost, clinical evaluation is key. With a typical necrotizing infection, surgery should not be delayed for the sake of a "perfect" diagnosis. Laboratory tests (complete blood count, C-reactive protein and procalcitonin levels, lactate, and kidney and liver function tests) help assess severity but do not replace clinical judgment. [19]

Bacteriological cultures are taken from deep tissue during initial surgical debridement, and in severe cases, blood cultures are also taken. Superficial smears are of little value. The results are needed for subsequent de-escalation of antibiotics. [20]

Imaging is useful for assessing the extent of the process and detecting gas. Plain radiography can show gas in soft tissues; ultrasound reveals fascial thickening and fluid; computed tomography quickly evaluates large areas and clearly shows gas and fascial necrosis; magnetic resonance imaging is most sensitive to deep soft tissue lesions. However, any imaging is acceptable only if it does not delay surgery. [21]

The Laboratory Risk Score for Necrotizing Fasciitis (LRINEC) can be helpful but should not be used to "rule out" the diagnosis: its sensitivity is insufficient, particularly for vibrio infections. A low score does not guarantee safety, while a high score often reflects severity and may have prognostic value. [22]

Table 7. "Quick minimum" of examinations for suspected wet gangrene

Direction	What to do immediately	For what
Laboratory	Complete blood count, biochemistry, lactate, C-reactive protein	Assessment of severity, sepsis, organ dysfunction
Microbiology	Blood cultures; deep wound culture from necrectomy	For targeted de-escalation of antibiotics
Visualization	X-ray/CT scan without delaying surgery	Search for gas and determine the extent of damage
Vascular status	Pulse palpation, ankle-brachial index, Doppler	Planning of revascularization in ischemia

What else could it be: differential diagnosis

In the early stages, wet gangrene can be confused with phlegmon, cellulitis, deep abscesses, deep vein thrombosis, and even gout. Key clues include pain that is clearly "worse than it looks," rapid worsening, and the failure of standard therapy to achieve the expected effect. Computed tomography and magnetic resonance imaging can help differentiate superficial infections from fascial and muscular lesions. [23]

It is critically important to differentiate critical ischemia from dry gangrene, where the pace and tactics are different. If severe ischemia is combined with infection, the condition is managed as wet gangrene: first, stabilization and debridement of the lesion, followed by revascularization. [24]

Table 8. Differences between necrotizing infection and “common” cellulitis

Sign	Necrotizing infection	Cellulite
Pain	Disproportionately strong	Matches your skin type
Pace	Hours-days	Days
Blisters/necrosis	Often	Rarely
Systemic signs	Expressed early	Later or moderately
Tactics	Immediate surgery + resuscitation	Antibiotics, observation

Treatment

The first step is sepsis treatment according to international guidelines. If signs of hypoperfusion or shock are detected, rapid fluid infusion is initiated: at least 30 milliliters per kilogram of crystalloids are recommended for the first 3 hours, with subsequent assessment of the response based on dynamic parameters. Maintain mean arterial pressure at approximately 65 millimeters of mercury using vasopressors if necessary. Early administration of antibiotics within the first hour improves outcomes. [25]

The second step is immediate surgery. Any delay in debridement increases mortality. The surgery involves wide excision of all non-viable tissue down to the "bleeding muscle," revision of the fascial spaces, and drainage. Repeat surgeries are planned in advance after 12-24 hours, because necrosis often "catches up" with visually healthy margins. In cases of extensive damage, amputation is performed, and in cases of Fournier's gangrene, diverting stomas for feces or urine are often created to protect the wound. The current trend in urology is to preserve as much viable skin as possible for future reconstruction. [26]

The third step is initial broad-spectrum antibacterial therapy. Until culture results are available, gram-positive cocci (including methicillin-resistant Staphylococcus aureus), gram-negative bacteria (including Pseudomonas aeruginosa in severely ill patients or in hospital settings), and anaerobes are covered. Typical combinations include piperacillin-tazobactam or a carbapenem plus an anti-methicillin-resistant Staphylococcus aureus drug (vancomycin or linezolid). If group A streptococcus is confirmed, clindamycin (or linezolid) is added to suppress toxin production, and beta-lactam (penicillin) is always retained, as it improves outcomes. [27]

Special situations require special regimens. For marine exposures with suspected vibrio infection, doxycycline plus ceftazidime is recommended, with a fluoroquinolone as an alternative; treatment should be initiated immediately, without waiting for confirmation. For freshwater injuries with a risk of Aeromonas infection, a fluoroquinolone in combination with a broad-spectrum beta-lactam is recommended until susceptibility testing is confirmed. [28]

The fourth step is source control and supportive care. This includes meticulous wound care, application of therapeutic vacuum (negative pressure), adequate pain relief, early enteral nutrition, blood sugar control in diabetes, and thrombosis prevention. In cases of severe limb ischemia, urgent revascularization is considered after initial debridement of the lesion. [29]

Hyperbaric oxygenation is considered as an additional option after debridement and with adequate antibiotic therapy. The data are mixed: some studies and clinical registries show benefit, but this approach should not delay surgery and standard resuscitation. The decision is made on an individual basis, based on experience and availability. [30]

Tetanus prophylaxis is also important: for any necrotic, contaminated wound, the vaccination history is assessed and, if indicated, anatoxin and immunoglobulin are administered. This is not antibiotic prophylaxis for tetanus, but post-exposure specific protection, which complements thorough surgical debridement. [31]

Fournier's gangrene often requires staged reconstruction: skin grafts and various types of flaps that gradually close the defects after stabilization. The timing of reconstruction depends on wound cleansing and the overall condition, as well as control of infection and metabolic factors. [32]

Once culture and sensitivity data are available, therapy is de-escalated to the narrowest yet most reliable regimen, typically for 10-14 days, and longer if bone tissue is involved. Any delay in initiating therapy or insufficiently radical initial surgery worsens outcomes more than the choice of a specific antibiotic. [33]

Table 9. Empirical schemes: benchmarks for sowing results

Clinical situation	Preferred modes before de-escalation
Severe soft tissue infection with risk of methicillin-resistant Staphylococcus aureus and anaerobes	Piperacillin-tazobactam or carbapenem + vancomycin or linezolid
Suspected streptococcal necrotizing fasciitis	Beta-lactam (penicillin) + clindamycin (or linezolid)
Sea water, vibrios	Doxycycline + ceftazidime; alternative: fluoroquinolone
Fresh water, aeromonads	Fluoroquinolone + broad-spectrum beta-lactam
Fournier's gangrene	Any of the "wide" modes + early multiple debridement

Prevention

Risk factor management is fundamental. For people with diabetes, achieving target blood glucose levels, regular foot examinations, proper footwear, ulcer treatment with early removal of necrotic tissue, and proper dressings and off-loading are crucial. This reduces the risk of infection and subsequent gangrene. [34]

Wound hygiene and injury prevention are the next layer of protection. Any wound should be cleaned, any debris removed, and prompt medical attention sought if signs of infection appear. For contaminated wounds, the need for tetanus protection should be assessed. [35]

Awareness of water exposures is important for fishermen, swimmers, and tourists: open wounds should not be immersed in warm seawater; any cut should be washed immediately after contact with water, and if it rapidly worsens, seek medical attention. [36]

Table 10. Prevention at three levels

Level	Measures
Primary	Glycemic control, smoking cessation, foot care, water safety
Secondary	Early treatment of ulcers and wounds, debridement, proper dressings, unloading the foot
Tertiary	Timely revascularization, prevention of relapse, patient education

Forecast: what does it depend on?

The key predictor of outcome is the time to the first radical necrectomy. Every hour of delay increases the risk of amputation and death. Prognosis is affected by advanced age, diabetes mellitus, multiple organ failure at admission, multidrug-resistant flora, and the need for extensive repeat debridements. [37]

Mortality from necrotizing soft tissue infections remains high according to current data, but with early combined management (intensive care, antibiotics, surgery), it is significantly reduced. In the case of Fournier's gangrene, modern approaches to sparingly preserving viable skin improve reconstruction outcomes and quality of life. [38]

Frequently asked questions

Is it possible to "wait it out" at home and start with bandages and antibiotics?
No. Wet gangrene is a surgical emergency. Any delay increases the risk of sepsis, amputation, and death. Home treatment is unacceptable. [39]

Is amputation always necessary?
No. The goal is to preserve as much viable tissue as possible. However, if the lesion is extensive and the blood supply cannot be restored, amputation saves lives and accelerates rehabilitation. The decision is made by a multidisciplinary team. [40]

Does hyperbaric oxygen therapy help?
It's an adjunctive treatment that sometimes improves outcomes, but it shouldn't delay surgery and antibiotics. It's used only where experience is available and only after initial debridement. [41]

How long should antibiotics be taken?
Typically 10-14 days, but the course and choice of medication depend on the depth of the lesion, culture results, and clinical progression. If bone is involved, treatment is longer. De-escalation by culture is mandatory. [42]

What should you do with vaccinations if the wound is dirty?
Check the date of the last vaccination. If the history is questionable, add tetanus immunoglobulin and administer the vaccination according to the schedule. All this complements thorough surgical debridement. [43]