Analysis of the increasing prevalence of necrotising fasciitis referrals to a regional plastic surgery unit: a retrospective case series.

Necrotising Fasciitis is a destructive infection of the skin and subcutaneous tissues associated with significant mortality and morbidity. Survival from the condition often necessitates patient referral for appropriate reconstructive surgery and supportive medical management. The aim of our study was to identify emerging patterns, characteristics and outcomes of necrotising fasciitis in Northern Ireland. A retrospective analysis of all patients referred to the Regional Plastic Surgery Service in Belfast between 2007 and 2012 was performed. Forty-six patients were identified with clinical, intraoperative and histopathological confirmation of necrotising fasciitis. Mean patient age was 59.4 years (range 32-88) with a 25:21 male to female ratio. 13 patients died from the disease. Smoking, obesity, diabetes and immunocompromise were the most prevalent co-morbidities identified. 37 patients had no identifiable mechanism of infection initiation in the history. Painful cellulitis (44/46), skin necrosis (26/46), skin blistering (8/46) and subcutaneous emphysema (3/46) were the most common presenting features. The median LRINEC score at presentation was 7 (range 2-12). The mean serum lactate at presentation was 4.0 mmol/L (range 1.6-13.5). LRINEC scores and serum lactate at presentation exhibited diagnostic sensitivities of 65% and 90% respectively. The lower extremity was the most commonly affected anatomical site (16/46). Group A Streptococcus was the most frequently isolated causative bacterium from debrided tissue cultures (16/46). The prevalence of necrotising fasciitis in the population studied is increasing, particularly in relation to patient cases caused by Group A Streptococcal infection. Increasing bacterial virulence and levels of patient immunocompromise may explain this increasing trend. The LRINEC scoring system lacked diagnostic sensitivity. Elevated serum lactate was supported as both a diagnostic and prognostic indicator. The findings of our study are somewhat limited in their application to other regions and highlight the need for a national analysis of necrotising fasciitis in the UK.