Risk factors

Infections in NF usually take place in a hypoxic environment with decreased function of polymorphonuclear leukocytes. Hence patients with NF usually have some predisposition to infection. Some known risk factors of NF include: (1)

• diabetes and other chronic medical diseases
• immunosuppressive drugs
• malnutrition
• advanced age e.g. - age >60 years
• IV drug use
• peripheral vascular disease
• obesity
• underlying malignancy

Clinicians should obtain specific history form patient to gather information about any precipitating events which might have caused NF. e.g. -

• traumatic event - surgery, IV drug use, penetrating injury
• non traumatic - soft tissue infections, burns, childbirth etc

It should be noted that around 25% of cases occur in patients without comorbidity or precedent trauma (2).

Reference:

1. Pasternack MS, Swartz MN. Cellulitis, necrotizing fasciitis, and subcutaneous tissue infections. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA: Elsevier; 2015:1194-215.
2. Sultan HY, Boyle AA, Sheppard N.Necrotising fasciitis. BMJ. 2012;345:e4274.