Necrotizing soft-tissue infections (NSTI) are rare and life-threatening bacterial infections characterized by subcutaneous tissue, fascia or muscle necrosis. Few prospective studies have been performed and our current knowledge on NSTI is mostly derived from retrospective single center studies. The "SKin and soft tissue necrotizing INfections in the ICU" (SKIN-ICU) study is a multinational prospective non-interventional cohort study that will include patients admitted to the ICU/intermediate care unit for NSTI or not.

The objectives of the study are :

1. To assess hospital (i.e., ICU and hospital mortality) and medium-term (day-90 mortality, functional outcomes and health-related quality of life scores, HR-QoL) outcomes
2. To report the clinical presentation and microbiological epidemiology of NSTI and identify independent prognostic factors of mortality and altered quality of life

Necrotizing soft-tissue infections (NSTI) are rare and life-threatening bacterial infections characterized by subcutaneous tissue, fascia or muscle necrosis. The mortality of NSTIs is high, ranging from 9% in non-selected patients to up to 30% in the most severe forms requiring intensive care unit (ICU) admission .

With an incidence of 4/100 000 persons per year, initial misdiagnosis is frequent, with no reliable diagnostic test available, frequently leading to a delayed surgical debridement of infected tissues, one of the main modifiable prognostic factors. According to international recommendations, any cutaneous infection associated with the failure of one or more organs or showing a dramatic deterioration must include the diagnosis of NSTI for consideration, even if there is no local sign of the condition being severe. The diagnosis is confirmed by identifying during surgery deficient tissue, sometimes necrotic, which comes away easily in the fingers and by the presence of the typical, foul-smelling "dishwasher" exudate.

The early management of NSTIs is challenging and requires a coordinated and multidisciplinary approach. Treatment of NSTIs consists of early broad-spectrum antimicrobial therapy together with emergency and aggressive surgical debridement including excision of all necrotic and infected tissues. Few prospective studies have been performed and our current knowledge on NSTI is mostly derived from retrospective single center studies.The few randomized therapeutic trials testing interventions in this setting have been disappointing, in part because of the difficulty to identify subgroups for individualized treatments. A large international study aimed at collecting granular data on the clinical presentation, microbiology, management and outcomes of patients with NSTI admitted in the ICU and involving a large number of centers and countries is thus desirable to improve our knowledge on this devastating condition.

The "SKin and soft tissue INfections in the ICU" (SKIN-ICU) study is a multinational prospective non-interventional cohort study that will include patients with NSTI admitted or not to the ICU/intermediate care unit and aim at addressing the following points: 1) Hospital (i.e., ICU and hospital mortality) and medium-term outcomes (three- and six-month survival, functional outcomes and health-related quality of life scores, HR-QoL); and 2) Clinical presentation and microbiological epidemiology of NSTI.

Inclusion Criteria:

• Age > 18 years
• Patient with surgically-confirmed NSTI (i.e., macroscopic appearance of tissue during surgery revealing swollen, dull gray tissues with a thin, brownish exudate with or without necrosis)

Exclusion Criteria:

• Patient deprived of liberty by judicial or administrative decision or patient under guardianship
• Expressed opposition to project's participation at the project

Patient with surgically-confirmed NSTI