Fournier gangrene is a surgical emergency characterized by rapidly progressive necrotizing fasciitis of the perineum, external genitalia, and perianal region. It differs from ordinary cellulitis in that infection tracks along fascial planes rather than remaining superficial, causing thrombosis of the subcutaneous vasculature that produces tissue ischemia and gangrene disproportionate to visible skin findings. The process is typically polymicrobial and synergistic, most often a mix of aerobic organisms (E. coli, Streptococcus, Staphylococcus) and anaerobes (Bacteroides, Clostridium), which together produce the foul odor, crepitus, and gas seen on imaging. Common portals of entry include anorectal abscess, urethral stricture with extravasation, perianal or scrotal skin trauma, and postoperative genitourinary or colorectal wounds. Major risk factors include diabetes mellitus, immunosuppression, chronic alcohol use, and peripheral vascular disease. Despite the eponym referencing male genitalia, the condition can occur in women (originating from the vulva or episiotomy site) and is coded the same regardless of sex. It is distinguished from generalized necrotizing fasciitis elsewhere on the body by its perineal/genital anatomic focus, which drives its own dedicated ICD-10-CM code, and from simple perianal abscess by the presence of systemic toxicity, crepitus, and fascial spread rather than a localized fluid collection.
eponymgreek
Named for Jean Alfred Fournier (1832-1914), a French dermatologist and venereologist who described idiopathic fulminant gangrene of the male genitalia in 1883. Unlike most terms in this dictionary, “Fournier” contributes no etymological root — it is a surname eponym, not a Greek or Latin combining form, so there is no prefix/suffix breakdown for that half of the term.
gangren-: from Greek gangraina (γάγγραινα), “an eating sore that spreads,” itself related to grainein, “to gnaw.” Refers to tissue death from loss of blood supply, here accelerated by microvascular thrombosis rather than large-vessel occlusion.
necr- + -osis: Greek nekros (“corpse, dead body”) + -osis (“abnormal condition”), together denoting the death of tissue.
Clinically, “Fournier gangrene” is treated as a fully specified, single anatomic-site synonym for necrotizing fasciitis of the perineum, so coders should cross-reference necrotizing fasciitis for the parallel non-eponymous term used at other body sites.
necrotizing fasciitis — the general (non-genital) form of the same fascial-plane infection process; coded to M72.6 when it occurs outside the perineum/genitalia.
Gas gangrene — clostridial myonecrosis caused specifically by Clostridium perfringens; coded to A48.0 and distinguished by muscle (not just fascia/subcutaneous) involvement.
cellulitis — superficial, non-necrotizing soft-tissue infection; lacks the fascial spread, thrombosis, and systemic toxicity that define Fournier gangrene.
sepsis / septic shock — frequent complication requiring separate, additional coding; drives MCC/HCC weight far more than the local infection code alone.
Ludwig’s angina — the head-and-neck anatomic analog of a rapidly spreading fascial-space infection, useful as a teaching comparison.
Hyperbaric oxygen therapy (HBOT) — adjunct treatment sometimes used post-debridement to improve tissue oxygenation and limit further necrosis.
Diverting colostomy — fecal diversion procedure sometimes performed when perianal/rectal source control requires it.
Unrelated procedure by the same physician during the postop period
⚠️ Coding Note:N49.3 is a single, fully specified code with no laterality or 6th-character site digits — resist the urge to search for a nonexistent “unspecified” or lateralized variant. When sepsis is documented and meets clinical criteria, sequence the underlying local infection (N49.3) first, then the sepsis code (A41.9) and, if applicable, the severe sepsis/septic shock code (R65.20/R65.21) — do not let the sepsis codes replace N49.3. Watch operative notes closely for staged debridements (11004-11006 performed on multiple dates): each session is separately reportable, and repeat trips to the OR within the global period typically need modifier -78, not -58, unless reconstruction was explicitly planned at the index operation. Diabetes (E11.65) and any documented organ dysfunction from sepsis should always be captured, as they carry substantial MCC/HCC weight that a bare N49.3 admission will otherwise understate. For inpatient PCS coding, excisional debridement of perineal subcutaneous tissue/fascia groups to the Medical and Surgical section, Excision root operation, body system 0J (Subcutaneous Tissue and Fascia) — verify the exact body part character for “Perineum” against the current PCS tables before finalizing, as this is a frequently mis-selected body part value.