Ruling out Fournier's Gangrene!

Dr. Spencer presents a case of a young man with untreated diabetes who presented with acute, progressive scrotal pain and swelling.

Our astute residents quickly raised concern for Fournier Gangrene which is an essential "rule out" diagnosis. However, Fournier Gangrene is challenging to diagnose and can only be definitively diagnosed with surgical evaluation.

Fournier Gangrene is a necrotizing fasciitis of the male genitalia (usually the scrotum and perineum but can involve the abdominal wall and penis). Though exceedingly rare, it should be considered in diabetic patients with scrotal cellulitis. SGLT-2 inhibitors have been associated with rare cases of Fournier Gangrene.

Physical Exam finding that raise concern for Necrotizing Fasciitis:

  • necrosis (maybe that's obvious)
  • pain out of proportion to exam
  • crepitus
  • subcutaneous air
  • bullae/blistering

Necrotizing skin and soft tissue infections can be polymicrobial (type I) or monomicrobial (type II, most likely Group A strep or Staph). Type I (polymicrobial) infections are more common in diabetics, patients who are immunocompromised, or patients who have recently had surgery.

We discussed the initial promise of the LRINEC score in diagnosing nec fasc, but highlighted that retrospective studies show inadequate sensitivity to rule out the diagnosis. LRINEC score includes CRP, WBC, sodium, glucose, creatinine, and hemoglobin. Despite its issues with sensitivity, it may help build your case when you call surgery for an urgent consultation!

A meta-analysis entitled "What is the Accuracy of Physical Examination, Imaging and the LRINEC Score for the Diagnosis of Necrotizing Soft Tissue Infection?" in the Annals of Emergency Medicine reviewed sensitivity, specificity, and positive and negative liklihood ratios of the following variables.

Treatment for Necrotizing Fasciitis:

1) surgical debridement!

1) empiric antibiotics

should cover gram positive, gram negative, anaerobic + clindamycin for antitoxin effect (inhibits protein synthesis)

examples:

  1. vancomycin + pipercillin/tazobactam + clindamycin

  2. vancomycin + ertapenem + clindamycin

  3. vancomycin + meropenem + clindamycin (if HC-associated)