Necrotising fasciitis

Question 1

Types

Answer 1

Type 1: caused by mixed anaerobes and aerobes (post-surgery in diabetics) and is the most common type

Type 2: cause by strep pyogenes

Question 2

Risk factors

Answer 2

Skin factors: recent trauma, burns or soft tissue infections

DM: most common preexisting medical condition, particularly if treated with SGLT2 inhibitors

IVDU

Immunosuppression

Question 3

Most commonly affected site

Answer 3

Perinium (Fournier’s gangrene)

Question 4

Features

Answer 4

Acute onset

Pain, swelling, erythema at the affected site

Often presents as rapidly worsening cellulitis with pain out of keeping with physical features

Extremely tender over infected area with hypoaesthesia to light touch

SKin necrosis and crepitus/gas are late signs

Fever and tachycardia may be absent or occur late in presentation

Question 5

Management

Answer 5

Urent surgical referral debridement

IV antibitoics

Question 6

Prognosis

Answer 6

Average mortality of 20%