CASE REPORT
A 51-year old male presented to our clinic with severe neck pain and massive swelling which was started as a furuncle-like lesion 14 days ago on the nape of the neck with rapid progression. He had refused to seek medical help due to the COVID-19 pandemic. He denied a history of DM and any trauma or bite in this location; however, there was a long history of occipital folliculitis. Besides, he had a history of hyperlipidemia and coronary artery bypass grafting surgery 1 year ago.
On clinical examination, there was a huge carbuncle with purplish color and multiple purulent sinus tracts (figure 1) with a limited range of motion due to extreme pain. Also, there were patches of cicatricial alopecia and tufted folliculitis on his occiput.
Laboratory exam revealed a blood glucose level of 537 g/dL and glycated hemoglobin A1c (HbA1c) of 13%. White blood cell count (WBC) was 14.60 (normal 4.00-11.00 x103/ul), erythrocyte sedimentation rate (ESR) 67 mm/hour, and C-reactive protein (CRP) 37.1 mg/L.
A preliminary diagnosis of carbuncle in the setting of uncontrolled DM was made. The differential diagnoses included actinomycosis, bite reaction, gas gangrene, and cutaneous anthrax. The patient developed rapid extension of erythema, warmness, and tenderness to the interscapular area and shoulders, along with confusion, fever, and tachypnea during the first hours of admission. So, NF was considered.
Soft tissue ultrasonography and neck computed tomography showed significant soft tissue thickening and increased echogenicity with fat lobulation. Some superficial foci of gas were noticed and interpreted as sinus tracts. No obvious abscess or collection was detected.
TazocinĀ® (piperacillin/tazobactam) plus vancomycin was started immediately after taking discharge samples for smear and culture and the patient was sent to the operation room for surgical debridement.
Intraoperatively a wide horizontal incision was made throughout the posterior neck. Extensive necrosis and pus formation extending deep into the muscles were observed spreading wide beyond the visible erythematous margin; therefore, a vertical incision was added to the interscapular area allowing complete evacuation of pus and necrotic tissues. Histopathologic examination revealed fibro adipose tissue with extensive abscess formation and necrosis. Cultures demonstrated the growth of staphylococcus aureus susceptible to methicillin, so the previous antibiotics were continued. Skin biopsy was obtained from the occiput that was compatible with folliculitis decalvans. Consecutive surgical debridement sessions for the next 7 days removed the whole necrotic tissues (figure 2). After ensuring that the necrosis spreading came to a halt, vacuum therapy was administrated for 12 days till granulation tissue filled the wound. After a total of 23 days of hospital admission, he was discharged with a shallow ulcer without any complications. The antibiotic regimen was changed to oral cotrimoxazole and clindamycin. Also, routine wound care and insulin therapy was continued, and weekly follow up for wound assessment was scheduled (figure 3). In 1 month follow up the wound was completely repaired.