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Title : A 54 year-old old female w/ right thigh pain
Date : August 15, 2010
Contributed by

Hyun Kyun Ki, M.D. Hae Suk Cheong. M.D.

Konkuk University Hospital, Korea

Patient History
Age/Sex A 54-yr old women
Chief complaint right thigh pain
Present illness

A 55 year-old women who had no medical history presented to the emergency department with right thigh pain for 5 days. She was being treated for right knee pain with steroid injection in right knee and inguinal area for the past one month in a local pain clinic. She had her last therapy 5 days earlier.

Physical examination

She had fever with low blood pressure and was tachycardic. Initial vital sign – BP 89/50 mmHg, BT 38.0℃, PR 131 bpm.

Initial laboratory findings

The CBC revealed 3510 (Neutrophil segmented 37%) >13.7<218K. The ESR was 42 mm/h and CRP 26.36 mg/dl. The level of AST/ALT was 41/91 IU/L and BUN/Cr was 35.7/1.6 mg/dl.

Radiologic findings

MRI – T1 weighted enhanced image of right thigh

Hospital course

The urgent exploration of the wound was arranged. On exploration, the infection was noted to extend along the plane of deep fascia over the whole anterior and medial aspect of the right thigh, with no evidence of subcutaneous gas collection.

Wound gram staining revealed Gram-positive cocci arranged in clusters.

Question - ID Case of the Week ( August 15, 2010 )
What is your diagnosis? And, what do you think the most likely causative organism?
Correct Answer

Necrotizing fascitis, Staphylococcus aureus (methicillin-sensitive)


Necrotizing fasciitis is a life-threatening infection of the superficial muscle fascia and adjacent subcutaneous tissue. These infections are typically caused by group-

A Streptococcus, a mixture of aerobic and anaerobic organisms, or organisms of the Clostridia species1. Staphylococcus aureus has been occasionally reported as a monomicrobial causative agent of necrotizing fasciitis. The afftected area is initially erytheramous, swollen, without sharp margins, hot, shiny, exquisitely tender, and painful. The progresses rapidly over several days, with sequential skin color changes from red-purple to patches of blue-gray. Within 3 to 5 days after onset, skin breakdown with bullae and frank cutaneous gangrene can be seen. Prompt diagnosis is of paramount importance because of the rapidity with which the process can progress. The reported mortality rate of necrotizing fasciitis has ranged from 24% to 34% overall. Early clinical differenciation of necrotizing fasciitis from cellulites can be difficult because the initial signs are not distinctive. However, the presence of marked systemic toxicity out of proportion to the local findings should alert the physician. Once the diagnosis is made, immediate surgical debridement is essential. Extensive incision should be made though the skin and subcutaneous tissues and should go beyond the area of apparent involvement until normal fascia is found. Antibiotics used before bacteriologic data are obtained include combinations of ampicillin, gentamicin, and metronidazole; ampicillin-sulbactam and gentamicin.


The Journal of Bone and Joint Surgery (American). 2006;88:1107-1110

Mandell, Douglas, and Bennett’s Principles and practice of Infectious diseases, 17th ed.


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