Fournier gangrene

WikiDoc Resources for Fournier gangrene
Articles
Most recent articles on Fournier gangrene Most cited articles on Fournier gangrene Review articles on Fournier gangrene Articles on Fournier gangrene in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Fournier gangrene Images of Fournier gangrene Photos of Fournier gangrene Podcasts & MP3s on Fournier gangrene Videos on Fournier gangrene
Evidence Based Medicine
Cochrane Collaboration on Fournier gangrene Bandolier on Fournier gangrene TRIP on Fournier gangrene
Clinical Trials
Ongoing Trials on Fournier gangrene at Clinical Trials.gov Trial results on Fournier gangrene Clinical Trials on Fournier gangrene at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Fournier gangrene NICE Guidance on Fournier gangrene NHS PRODIGY Guidance FDA on Fournier gangrene CDC on Fournier gangrene
Books
Books on Fournier gangrene
News
Fournier gangrene in the news Be alerted to news on Fournier gangrene News trends on Fournier gangrene
Commentary
Blogs on Fournier gangrene
Definitions
Definitions of Fournier gangrene
Patient Resources / Community
Patient resources on Fournier gangrene Discussion groups on Fournier gangrene Patient Handouts on Fournier gangrene Directions to Hospitals Treating Fournier gangrene Risk calculators and risk factors for Fournier gangrene
Healthcare Provider Resources
Symptoms of Fournier gangrene Causes & Risk Factors for Fournier gangrene Diagnostic studies for Fournier gangrene Treatment of Fournier gangrene
Continuing Medical Education (CME)
CME Programs on Fournier gangrene
International
Fournier gangrene en Espanol Fournier gangrene en Francais
Business
Fournier gangrene in the Marketplace Patents on Fournier gangrene
Experimental / Informatics
List of terms related to Fournier gangrene

Steven C. Campbell, M.D., Ph.D.; Associate Editor(s)-in-Chief: Yamuna Kondapally, M.B.B.S[1]; Jesus Rosario Hernandez, M.D. [2]

Synonyms and keywords: Idiopathic gangrene of scrotum; Periurethral phlegmon; Streptococcal scrotal gangrene; Genito-perineal gangrene; Phagedena

Fournier gangrene
ICD-10	N49.8 (ILDS N49.81), N76.8
ICD-9	608.83
DiseasesDB	31119
MeSH	D018934

Overview

Fournier gangrene is a type of synergistic polymicrobial necrotizing infection (gangrene) of the perineal, genital or perianal regions usually affecting the male genitals but can also occur in female and children. It is a fulminant form of necrotizing fasciitis. It was first described by Baurienne in 1764 and is named after a French venereologist, Jean-Alfred Fournier following five cases he presented in clinical lectures in 1883.

Historical Perspective

• Fournier's gangrene was first described by in 1764 by Baurienne.
• The detailed description of fournier's gangrene was given by Jean Alfred Fournier, who is a French venereologist in 1883.

Classification

The ICD 10 classification of Fournier's gangrene include:

• ICD-10: N49.3
• Code Classification

• Diseases of the genitourinary system

• Diseases of male genital organs (N40-N53)

• Inflammatory disorders of male genital organs, NEC (N49)

Pathophysiology

• The transmission of pathogens occurs through the following routes:

• External trauma (e.g., laceration, abrasion, burn, insect bite)
• Direct spread from a perforated viscus (particularly colon, rectum, or anus) or another surgical procedure (e.g., vasectomy, hemorrhoidectomy)
• Urogenital organ
• Perirectal abscess
• Decubitus ulcer

• Following transmission, the bacteria uses the entry site to invade the fascial planes which causes the wide spread necrosis of superficial fascia, deep fascia,

subcutaneous fat, nerves, arteries, and veins.

• Superficial skin and deeper muscles are typically spared.
• In late stages, lesions develop liquefactive necrosis at all tissue levels.

Pathogenesis

• The pathogenesis of fournier's gangrene is the result of an imbalance between bacterial and host factors.

• Host factors: Decrease in host immunity provides favourable environment to initiate the infection
• Bacterial factors: Virulence and synergism between multiple bacteria promotes rapid spread of infection

• The aerobic and anaerobic bacteria produce exotoxins and enzymes like collagenase, heparinase, hyaluronidase etc which promote spread of infection.
• The aerobic bacteria cause acceleration of coagulation by promoting platelet aggregation and complement fixation and the anaerobic bacteria produce collagenase and heparinase that promote the formation of clots leading to obliterative endarteritis.
• The cutaneous and subcutaneous vascular necrosis develops leading to local ischemia and further bacterial proliferation.
• The infection spreads from superficial (colles fascia) and deep fascial planes of genetalia to the overlying skin sparing the muscles. The infection then spreads from colles fascia to the penis and scrotum via Buck's and Dartos fascia or to the anterior abdominal wall via Scarpa's fascia or vice versa.
• The inferior epigastric and deep circumflex iliac arteries (supply anterior abdominal wall), and external and internal pudendal artery supply the scrotal wall. Except internal pudendal artery, each of these vessels travels with in Camper's fascia and can therefore become thrombosed in the progression of fournier's gangrene.
• The progression of infection to the perineal body, urogenital diaphragm and pubic rami is limited due to perineal fascia.
• Because of direct supply of blood from aorta, testicular involvement is limited in Fournier's gangrene. However involvement of testis suggests retroperitoneal origin or spread of infection.
• Fournier's gangrene of the male genetalia spares testes, urethra and deep penile tissues while the skin sloughs off.
• Sepsis and multiorgan failure is the most common cause of death in Fournier's gangrene.

Common locations

The common locations of Fournier's gangrene are:

• Perineum
• Scrotum
• Penis

Gross pathology

On gross pathology, the characteristic findings of Fournier's gangrene include:

• Subcutaneous emphysema
• Swollen scrotal wall
• Edema
• Erythema
• Bullae
• Skin sloughing

Microscopic histopathological analysis

On microscopic histopathological analysis, the characteristic findings of Fournier's gangrene are:

• Early stages

• Obliterative vasculitis with microangiopathic thrombosis
• Acute inflammation of subcutaneous tissue
• Superficial hyaline necrosis along with edema and inflammation of the dermis and subcutaneous fat
• Dense neutrophil-predominant inflammatory infiltrate

• Late stages

• Noninflammatory intravascular coagulation and hemorrhage
• Myonecrosis

• 
  Histology of excised skin shows full thickness, featureless, coagulative necrosis with no viable tissue remaining
• 
  Histology of excised scrotal skin shows zones of neutrophil polymorph infiltration, with embedded foreign material possibly representing hair shafts
• 
  Histology of excised skin shows bacterial colonies (cocci and bacilli) in the superficial zone

Causes

Fournier's gangrene is caused by mixed aerobic and anaerobic organisms which normally exist below the pelvic diaphragm in the perineum and genitalia. Fournier's gangrene may be caused by the following organisms:

Bacteria

Aerobic organisms Most common aerobic organisms are:

• Group A streptococcus
• Escherichia coli
• Klebsiella pneumoniae
• Staphylococcus aureus

Anaerobic organisms Most common anaerobic organisms are:

• Bacteroides fragilis

Other organisms

• Streptococcus
• Enterococcus
• Coryebacterium
• Clostridium
• Pseudomonas
• Proteus species
• Candida species
• Lactobacillus gasseri

Idiopathic

Less than quarter of cases of fournier's gangrene are idiopathic.

Differentiating Fournier gangrene from Other Diseases

Fournier's gangrene must be differentiated from other diseases that cause pain, swelling erythema, discharge and raised temperature such as:

• Scrotal abscess
• Herpes simplex
• Cellulitis
• Strangulated hernia
• Streptococcal necrotizing fasciitis
• Gonococcal balanitis and edema
• Vascular occlusion syndromes
• Allergic vasculitis
• Pyoderma gangrenosum
• Necrolytic migratory erythema
• Ecthyma gangrenosum
• Warfarin necrosis
• Polyarteritis nodosa

Epidemiology and Demographics

Incidence

Incidence of Fournier's gangrene in the United states:

• The overall incidence of Fournier's gangrene annually are 1.6 cases per 100,000 males.The incidence peaked and remained steady after age 50 at 3.3 cases per 100,000 males.
• The incidence of Fournier's gangrene increased 0.2 per 100,000 males for each 1% increase in the regional prevalence of diabetes.
• The incidence rate was highest in the south and the lowest in the west and Midwest US.

• 
  Distribution of annual cases per hospital.

Age

Fournier's gangrene affects individuals of all ages but commonly affects individuals older than 50 years of age.

Gender

Men are more commonly affected with fournier's gangrene than women (male:female ratio is 10:1).

Mortality

• Mortality rate decreases with early aggressive treatment.
• The mortality rate of Fournier's gangrene is between 20% to 80%. Higher mortality rates are found in daibetics, alcoholics and those with colorectal sources of infection.

Risk Factors

Common risk factors in the development of fournier's gangrene are:

• Comorbid systemic disorders

• Age>50 yrs
• Male Gender
• Diabetes mellitus
• Alcohol misuse
• Immunosupression
• Chemotherapy
• Chronic corticosteroid use
• HIV
• Leukemia
• Liver disease
• Debilitating illness
• Malignancy
• Cytotoxic drugs

The most common foci of fournier's gangrene include:

Anorectal	Genitourinary	Dermatology	Gynaecological
Trauma Steroid enemas for radiation proctitis Hemorrhoidectomy Anal fissures excision Diverticulitis Colonic perforations Ischiorectal, perirectal, or perianal abscesses Appendicitis Steroid enemas for radiation proctitis	Trauma Cancer invasion to external genitalia Hemipelvectomy Epididymitis or orchitis Penile artificial implant or a foreign body Hydrocele aspiration Genital piercing Intracavernosal cocaine Urethral catheterization or instrumentation Penile implantsinsertion Prostatic biopsy Vasectomy Urethral strictures with urinary extravasation	Blunt perineal trauma Intramuscular injections Genital piercings Scrotal furuncle Perineal or pelvic surgery/inguinal herniography	Episiotomy wound Infected bartholins gland Septic abortion Genital mutilation Coital injury

Neonates and Children

• Trauma
• Burns
• Insect bites
• Circumcision

Screening

According to the U.S. Preventive Service Task Force (USPSTF), there is insufficient evidence to recommend routine screening for Fournier's gangrene.

Natural History, Complications, and Prognosis

Natural history

• If left untreated, the acute inflammatory changes spread quickly, accompanied by high fever and extreme weakness.
• The overlying skin becomes smooth, tense and shiny. Diffuse erythema without distinct borders is seen.
• First 1 or 2 days, the lesions develop with progressive colour changes from red to purple to blue and then becomes frankly gangrenous, first turning black, then greenish yellow.
• If the patient has survived, a line of demarcation between viable and necrotic tissue would become sharply defined from days 7 to 10.
• Sloughing of necrotic skin would reveal the underlying pus and extensive liquefactive necrosis of subcutaneous tissues, which will be significantly more extensive than would be suspected with the overlying area of necrotic skin.
• Metastatic abscesses and pulmonary distress may develop as well.

Complications

Common complications of Fournier's gangrene include:

Reported complications

• Renal failure
• Acute respiratory distress syndrome
• Heart failure
• Cardiac arrhythmias
• Septic metastasis
• Urinary tract infection
• Stroke
• Acute thrombo embolic disease of lower extremities

Surgical complications

• Wound infection
• Stoma-related complications
• Prolonged ileus (7 days)
• Eventration or evisceration

Long term complications

• Pain (50% of patients)
• Impaired sexual function (due to penile deviation/torsion, loss of sensitivity of the penile skin or pain during erection)
• Stool incontinence
• Extensive scarring

Prognosis

Depending on the underlying comorbidities, the prognosis of Fournier's gangrene varies. Few of the prognostic factors include:

• Severe sepsis
• Affected area calculation/Extension of the necrosis

• <3% of body surface area rarely die
• ≥5% of body surface area have worse prognosis

Diagnosis

The diagnosis is primarily based on clinical findings.

Diagnostic Criteria

The Uludag Fournier's gangrene severity index

Physiologic Variables	High Abnormal Values				Normal	Low Abnormal Values
	+4	+3	+2	+1	0	+1	+2	+3	+ 4
Temperature	>41	39-40.0		38.5-39	36-38.4	34-35.9	32-33.9	30-31.9	<29.9
Heart Rate	>180	140-179	110-139		70-109		55-69	40-54	<39
Respiratory Rate	>50	35-49		25-34	12-24	10-11	6-9		<5
Serum Sodium (mmol/L)	>180	160-179	155-159	150-154	130-149		120-129	111-119	<110
Serum Potassium (mmol/L)	>7	6-6.9		5.5-5.9	3.5-5.4	3-3.4	2.5-2.9		<2.5
Serum Creatinine (mg/100/ml*2 for acute renal failure)	>3.5	2-3.4	1.5-1.9		0.6-1.4		<0.6
Hematocrit	>60		50-59.9	46-49.9	30-45.9		20-29.9		<20
WBC (Total/mm*1000)	>40		20-39.9	15-19.9	3-14.9		1-2.9		<1
Serum Bicarbonate (Venous,mmol/l)	>52	41-51.9		32-40.9	22-31.9		18-21.9	15-17.9	<15

• Score >10.5 indicates 96% probability of death
• Score ≤10.5 indicates 96% probability of survival

According to Loar and colleagues, the severity of Fournier's gangrene is:

• Score ≥9 indicates 46% probability of death
• Score <9 indicates 96% probability of survival

Laboratory risk indicator for necrotizing fasciitis (LRINEC) scoring system

• LRINEC is a diagnostic scoring system used to distinguish necrotizing fasciitis from other soft tissue infections.
• It was first established by Wong et al in 2004.
• Risk assessment of necrotizing faciitis using LRINEC score:

• Low risk: ≤5
• Intermediate risk: 6-7
• High risk: ≥8

Variable	Score
C reactive protein (mg/dL) <150 >150	0 4
Total white blood cell count (/mm3) <15 15-25 >25	0 1 2
Hemoglobin (g/dL) <13.5 11-13.5 <11	0 1 2
Sodium (mmol/L) ≥135 <135	0 2
Creatinine (μmol/L) <141 >141	0 2
Glucose (mmol/L) <10 >10	0 1

History

A detailed and thorough history from the patient is necessary. Specific areas of focus when obtaining a history from the patient include:

• Trauma
• Alcohol misuse
• Immunosupression
• Chemotherapy
• Chronic corticosteroid use
• HIV
• Leukemia
• Liver disease
• Debilitating illness
• Malignancy
• Cytotoxic drugs
• Abdominal disease
• Surgery
• Epididymitis or orchitis

Symptoms

The symptoms of Fournier's gangrene include:

• Pain and selling in the scrotum
• Erythema
• Discoloration of involved skin
• Purulence or wound discharge
• Pallor
• Fever>38°C
• Crepitation
• Prostration
• Fluctuance
• Fetid odour

Physical examination

Gallery

Genitourinary system

• 
  url = http://www.atlasdermatologico.com.br/disease.jsf?diseaseId=157>
• 
  url = http://www.atlasdermatologico.com.br/disease.jsf?diseaseId=157>
• 
  url = http://www.atlasdermatologico.com.br/disease.jsf?diseaseId=157>
• 
  url = http://www.atlasdermatologico.com.br/disease.jsf?diseaseId=157>
• 
  url = http://www.atlasdermatologico.com.br/disease.jsf?diseaseId=157>

Laboratory Findings

Laboratory findings consistent with the diagnosis of Fournier's gangrene include:

• CBC with differential count
• Culture of open wound or abscess
• Disseminated intravascular coagulation panel

• Coagulation studies(PT, aPTT, thrombin time etc)
• Fibrinogen/fibrin degradation product levels

• Blood culture
• Urine culture
• Arterial blood gas analysis
• Electrolyte panel
• Blood urea nitrogen (BUN)
• Creatinine
• Blood glucose levels

Imaging Findings

The diagnosis of Fournier's gangrene is based on clinical findings.The role of imaging includes:

• Diagnosis not established
• Determine the extent of disease
• Detect underlying cause

Radiography

• On X-ray, Fournier's gangrene is characterized by:

• Subcutaneous gas or soft tissue swelling (specific x-ray finding) seen extending from scrotum and perineum to the inguinal regions, anterior abdominal wall, and thighs.
• Increase in the soft tissue thickness and opacity.

• Plain x-ray is a poor screening study for Fournier's gangrene because:

• Subcutaneous emphysema is an insensitive finding and is present in a minority of patients
• In the early stages the findings are similar to cellulitis

Ultrasound

On ultrasound, Fournier's gangrene is characterized by:

• Thickened scrotal wall
• Echogenic gas foci in scrotum pathognomonic-Seen as dirty shadowing
• Testes and epididymi spared (due to their separate blood supply)
• Reactive unilateral or bilateral hydroceles are present
• Differentiate Fournier gangrene from inguinoscrotal incarcerated hernia (In inguinoscrotal incarcerated hernia gas is observed in the obstructed bowel lumen, away from the scrotal wall)

Computed tomography

The CT of Fournier's gangrene is characterized by:

• Soft tissue stranding and fascial thickening
• Soft tissue gas
• The extent of disease can be assessed prior to surgery
• A cause of infection may be apparent(e.g.perineal abscess, fistula)

MRI

On MRI, Fournier's gangrene is characterized by:

• Edema and inflammation of skin and subcutaneous planes of the scrotum and perineal planes
• Subcutaneous emphysema

Gallery of Imaging Findings

• 
  X ray of Fournier's gangrene
• 
  Ultrasound of Fournier's gangrene
• 
  CT of Fournier's gangrene
• 
  CT of Fournier's gangrene with spontaneous perforation of rectal cancer

Treatment

Medical Therapy

Fournier gangrene is a urological emergency requiring intravenous antibiotics and debridement (surgical removal) of necrotic (dead) tissue. Despite such measures, the mortality rate overall is 40%, but 78% if sepsis is already present at the time of initial hospital admission.

Antimicrobial Therapy

• Fournier gangrene

• If caused by streptococcus species or clostridia

• Preferred regimen: Penicillin G

• Polymicrobial

• Preferred regimen: Doripenem OR imipenem OR meropenem

• MRSA (methicillin resistant staphylococcus aureus) suspected

• Preferred regimen: vancomycin OR daptomycin

External links

• Template:WhoNamedIt2 and Template:WhoNamedIt