About necrotizing fasciitis

There has recently been considerable media coverage about a few cases of necrotizing fasciitis (NF) reported in Britain. NF is an acute necrotizing cellulitis that involves the superficial fascia and subcutaneous fat. The outstanding characterization in infection is extensive undermining of surrounding tissue, which may result in patchy cutaneous anesthesia gangrene and even death.

There are two main bacterial causes of NF: Streptococcus pyogenes and a syngergistic infection with facultative and anaerobic bacteria, usually of bowel origin. Streptococcal and mixed infections are painful and rapidly progressive, with prominent systematic toxicity and similar skin changes.

The features of the disease suggest that most cases occur from one of three mechanisms:

Early NF may be indistinguishable from typical acute cellulitis. Prompt diagnosis of NF is essential because it correlates strongly with a better outcome.

In London, the public health laboratory service is assisting in the investigation of a cluster of NF cases in the Gloucester area. The condition is rare and would normally account for fewer than l0 reported cases in any given year from all bacterial causes, including Group A Streptococcus.

The evidence so far indicates that the organisms isolated from the Gloucester cases are within the range. The type and number of necrotizing conditions that could he expected to occur normally have been demonstrated by microbial investigations of the Gloucester cases to be of different subtypes of Group A Streptococcus and of the various types that would routinely be encountered.

Microbiological investigations looking at toxin production have demonstrated different combinations of toxin genes that also have been within the normally expected results. Consideration is being given to what other microbiological investigations might be fruitful; however, additional tests would involve other research groups and results would not be forthcoming rapidly.

Cases of NF have been occurring for years in many countries but are not usually reported in the popular press. The cases in Britain attracted attention not because they represent a new disease, but because by chance several cases occurred in the same district. All countries have a good system of disease surveillance and record the incidence of complications. For example, in the United States an average of 150 to 300 people per year develop NF.

There are no specific preventive or control measures other than the usual basic principle of not neglecting skin infections or wounds, even if they are small.

They should be treated quickly and properly.

The causative agent is very sensitive to antibiotics. It is also necessary to maintain aseptic techniques in case any invasive procedure is undertaken, no matter how small or simple it may seem.