Seen in the ED Quiz: Progressive Buttock Pain

Patient history. A woman in her forties presents to the emergency department complaining of 3 days of generalized malaise and worsening left buttock pain with subjective fevers. She vomited once but denies any abdominal pain, diarrhea, or headache. She denies chills or any other complaints.

Examination. Vital signs were a bit “soft” with a pulse of 102 beats/min and a BP of 92/51 mm Hg, corresponding to a shock index >1.0 (HR/SBP). Physical examination was otherwise normal except for a red swollen left buttock area.

Laboratory testing

• WBC = 17 with 16 bands
• Lactic acid = 2.6 mmol/L

Due to the soft vitals, bandemia, and elevated lactic acid a CT scan was done (case image below) to see if there was any abscess or other reason for a surgical consult.

What’s the most likely diagnosis?

1. Uncomplicated cellulitis
2. Perirectal abscess
3. Necrotizing fasciitis
4. Pyomyositis

Nec-Fasc fromThe Emergency Medicine 1-Minute Consult Pocketbook