Necrotizing fasciitis: a 10-year retrospective study of cases in a single university hospital in Oman
1Department of Surgery, P.O. Box: 38, Sultan Qaboos University Hospital, Postal Code: 123, Muscat, Oman. mohan.r@omantel.net.om
Objective:
(1) To study the clinical profile of all cases of necrotizing fasciitis (NF) diagnosed in a university hospital in Oman. (2) To evolve a strategy for early diagnosis.
Patients And Methods:
The inpatient records of the Sultan Qaboos University hospital from 1990-99 were searched for the words "fasciitis", "necrosis" or "gangrene" and cases of NF (defined as a soft tissue infection characterized by widespread necrosis of the subcutaneous tissues confirmed at surgery or pathology or both) were selected and analyzed. Cases with necrosis due to other obvious causes were excluded.
Results:
Of the seven cases of NF (hospital incidence-8.4/10(5)), there were three post-operative, three spontaneous and one post-traumatic. Sites involved: upper limb (1), lower limb (2), abdomen (2), gluteal (1), and breasts (1). The median age was 50 years (range 21-85) and the male:female ratio was 4:3. All patients had local pain out of proportion to the signs and six had fever. Hypotension, liver or kidney dysfunction or coagulopathy were seen in four and a drop in haemoglobin was seen in six. In none was NF even considered by the referring or admitting physician, diagnosis being delayed by 2-10 days. In four cases a diagnostic incision under local anesthesia revealed the correct diagnosis. At surgery, extensive fascial and fat necrosis were seen in all, but only two had myonecrosis. The commonest isolate was beta-hemolytic group D streptococcus (4/7). Blood and tissue were positive for beta-hemolytic group A streptococci in one fatal case. Mean hospital stay was 54.5 days (11-134), mean surgical procedures were 2.3 per case, two required ICU admission with one death.
Conclusion:
NF is a rare but serious bacterial disease that is often incorrectly diagnosed. Unexplained severe local pain, deep tenderness without impressive local signs, fall in haemoglobin, organ system dysfunction and constitutional upsets were regular features. A high index of suspicion and immediate direct inspection of the fascia facilitates an early diagnosis.