VOL: 96, ISSUE: 38, PAGE NO: 12
Martin Kiernan, MPH, RGN, ONC, DipN, is senior clinical nurse specialist, control of infection, Southport and Ormskirk Hospital NHS Trust
Fournier’s gangrene is a form of necrotising fasciitis that affects the scrotum and male perineum. If it is diagnosed early, prompt surgical intervention may prevent extensive infection and tissue damage. Left too late, the tissue damage is often so severe that the patient may not recover: one study revealed a fatality rate of 43% (Laor et al, 1995).
Aetiology and clinical presentation
The aetiology of Fournier’s gangrene is poorly understood, but certain characteristics of the disease have been described. Prodromal symptoms, such as scrotal pain for a few days before the onset of gangrene, are common. Other factors include predisposing sepsis of the urethra.
Once established, the gangrene usually progresses rapidly. The testes and the anal margin are not usually affected because they have an alternative blood supply.
Edmondson et al (1992) suggest that an infection in the urinary tract or lower gastrointestinal tract spreads to the superficial perineal space, affecting the blood supply and causing ischaemia in the tissues. In an already debilitated patient, the presence of pathogenic bacteria working synergistically may be responsible for the condition.
From the outset there is pain, oedema and redness of the skin that progresses to dark discoloration, blistering and finally ulceration. Beneath the surface tissues, subcutaneous necrosis occurs simultaneously and may lead to severe toxaemia.
Apart from being male, the risk factors include impaired immune function, for example as a result of malignancy or steroids, and a previous physiological event, such as trauma, surgery or urinary catheterisation (Karim, 1984). Diabetes mellitus is also often associated with Fournier’s gangrene (Archer, 1986).
The microbiological picture is often complicated. The infection may be caused solely by group A streptococci (Streptococcus pyogenes), but the origin may also be polymicrobial, with organisms such as bacteroides, fusobacterium, Staphylococcus aureus and coliforms implicated (Neal, 1999)
Some of these bacteria work together synergistically to create a more aggressive and invasive disease.
Tissue from debridement is usually sent to a laboratory for culture and sensitivity tests. Surface wound swabs are not likely to identify the causative organisms because the results can easily be confused by the presence of organisms colonising the skin in the perineal area. The target organisms will only reliably be found in the affected tissues, the fascia.
Treatment usually involves excision of the affected fascia and the administration of broad-spectrum antibiotic therapy.
Systemic antibiotic therapy must not be delayed until the results of microbiological tests are available. Once the test results are known, the therapy can be altered to target the specific organisms responsible for the infection.
Early diagnosis of this form of necrotising fasciitis is likely to result in a favourable outcome for the patient, although there is often less chance of successful treatment in older men (Laor et al, 1995). With any sign of necrosis, inflammation or pain in the scrotum or male perineum, Fournier’s gangrene should always be considered and the patient should always be followed up so that infection does not remain undetecte.