In 1883 Fournier described the gangrene as idiopathic, of sudden presentation and rapidly developing in previously healthy young males.1
This definition has changed substantially. Today an underlying etiology can almost always be identified and the disease is not limited to young people or to males.14,15
This population based epidemiological study provides a different perspective than that provided by previous studies. We confirmed that Fournier’s gangrene is rare by providing data that Fournier’s gangrene represents less than 0.02% of hospital admissions with an overall incidence of 1.6 cases per 100,000 males. Overall no patients with Fournier’s gangrene were treated at 66% of hospitals during a given year and 5 or more per year were treated at only 1% of hospitals. Thus, even at the highest volume centers a patient with Fournier’s gangrene was treated only every few months.
In 1972 Stone and Martin reported an 88% mortality rate in 33 patients with Fournier’s gangrene.2
Although contemporary published series indicate a fatality rate in the 20% to 40% range, this population based study showed a substantiality lower mortality rate of 7.5% (). Even in transferred patients, possibly representing the most acutely ill patients, the mortality rate was only 12.7%. In the largest study of Fournier’s gangrene Eke reviewed 1,726 cases from the English literature and reported an overall mortality rate of 16%,16
more than double the 7.5% rate in our study. The case fatality rate in patients with Fournier’s gangrene in our study is less than the 24% rate in previous reports of group A streptococcal necrotizing soft tissue infections based on the Centers for Disease Control and Prevention population based surveillance system, supporting the often less lethal course of Fournier’s gangrene compared to that of other necrotizing soft tissue infections.17
Using a population based approach allowed us to identify how a large number of Fournier’s gangrene cases were managed at multiple centers, including tertiary care referral hospitals and nonreferral hospitals, limiting case selection and publication bias.
Contrary to the original description of Fournier, only 26% of patients in our study had no coded comorbidity and only 23% were younger than 40 years old. Fournier’s gangrene does not occur exclusively in males but our efforts to identify a comparable cohort of females revealed only 39 patients. Because of the differences in case ascertainment, our analysis focused on male cases.
This series has important limitations. The study was retrospective, using administrative data, and subject to the inherent biases of these study designs. There were no available clinical or microbiological variables in the data set18–20
to allow us to confirm the diagnosis, determine the degree/severity of infection or the percent of surface area of skin involvement, or calculate a Fournier’s gangrene severity index. We were unable to explore urethral stricture disease as a precipitating comorbidity since this was not captured as comorbidity in the data set. Differential coding of comorbidities was possible with comorbidities more likely to be captured in more severely ill patients and in those who died. We may have excluded patients with Fournier’s gangrene who were treated with antibiotics only because our case definition required surgical débridement. However, our subgroup analysis revealed that these patients likely did not merit a diagnosis of Fournier’s gangrene. It is possible that the case fatality rate was inflated because we included all patients who died with a Fournier’s gangrene diagnosis code but required all survivors to have a Fournier’s gangrene diagnosis code as well as genital/perineal débridement. We have limited information on women due to ICD-9 coding limitations.
To our knowledge this is the largest study of Fournier’s gangrene and the first population based study allowing an accurate estimation of incidence and case fatality. Our study provides needed data on managing this complex condition in the United States. Unfortunately to our knowledge there are no comparable data with regard to incidence rates in other parts of the world. We provide new insights into the rarity and hospital experience with Fournier’s gangrene, regional trends and the association of Fournier’s gangrene with other comorbidities. Our findings agree with prior literature on age at onset and comorbid risk factors, although we found substantially lower mortality than reported in case series from tertiary referral centers. Further study is necessary to explore potential differences in treatments and outcomes in patients with Fournier’s gangrene at different types and sizes of hospitals, and explore the impact of hospital experience with Fournier’s gangrene.