What is FG?
A form of necrotising fasciitis that affects the perineum.
It is a urological emergency with mortality rate of 20-40%.
Monomicrobial or polymicrobial
Group A streptococcus
Spread of FG
Based on scrotal anatomy
Anatomic barriers include the dartos fascia of the penis and scrotum.
Colles fascia of the perineum
Scarpa fascia of the anterior abdominal wall.
This all means that the testes and epididymis are commonly not affected.
Poor nutritional status
Recent trauma to the region
Severe pain out of proportion to clinical signs
Usually non-specific and it usually looks "not quite right" for simple cellulitis
Crepitus, skin necrosis and haemorrhagic bullae might present as the condition progresses.
Sensory loss of overlying skin
Patients rapidly deteriorate and become significantly unwell.
Sepsis and septic shock to follow
Diagnosis is largely clinical and should be taken for immediate surgical exploration
Routine bloods with blood cultures should be taken
CT might be done which can show fascial swelling and soft tissue gas, but it should not delay surgical exploration
Risk scoring for necrotising fasciitis
Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC)
Based on laboratory factors a score of 6 or more is a reasonable score to consider the diagnosis on lab results alone.
Urgent surgical debridement
Partial or total orchiectomy as well depending of the size of expansion.
Broad-spectrum abx + transfer to high-dependency setting
Fluid resus and close monitoring
Further surgical debridement is commonly required.
Secondary close with skin grafts can be a long process with variable outomces.