James L. Mahoney, MD, FRCSC
I am always concerned when I receive a culture report in any wound identifying Group A Streptococcus, also reported as streptococcus pyogenes.
This bacterium is associated with a much more severe infection, suggested by the local clinical findings. In addition, sepsis with significant multi-system involvement, including kidney and respiratory failure, can be seen.
Concern is always present after a penetrating injury, however, these infections can present without it, as highlighted by a recent case.
A 55-year-old man was referred from a regional hospital after a presentation of swelling in his right hand over a 24-hour period. The entire hand was swollen and red, extending up to the wrist. Findings were more localized to the palm, but diffuse tenderness was present. Of concern was the development of high fever and signs of toxicity, with unstable blood pressure. His laboratory finding were consistent with sepsis. Again, to emphasize, there was no history of trauma.
The most likely diagnosis was felt to be a deep hand infection. He was taken to the operating room urgently after his arrival, where exploration was performed through a longitudinal mid palmar incision.
Diffuse soft-tissue findings in all tissue planes without involvement of the tendons were found. No localized collections were identified. Dorsal and palmar localized swellings included skin change similar to bruising in the digits. Cultures taken from the wound fluid identified Group A Streptococcus, sensitive to Penicillin and Clindamycin. He was placed on intravenous antibiotics and left intubated.
As the redness progressed proximally over the next 24 hours, he was again taken to the operating room for more extensive exploration of the forearm and upper arm fascia. Edema was identified. The muscle was viable. In the hand, he had developed skin necrosis along the edges of the palmar wound, in the PIP flexion crease of the index finger, and over the dorsum of his hand. These areas had only looked bruised the day before.
Systemically, he improved and was extubated a day later. The diffuse swelling in his hand has gone on to settle over three weeks. The skin involvement in terms of the localized swelling and blistering has progressed to full thickness skin loss. Two more surgeries have been required for soft-tissue debridement, and one for skin grafting. He has required hospitalization for 25 days.
I have managed necrotizing fasciitis in the lower extremity, shoulder and chest, where the presentation has been similar.
Clinically, localized redness, pain out of proportion and toxicity in a patient who initially appeared to have cellulitis raises the possibility. Differential diagnosis included compartment syndrome, and some have considered acute venous thrombosis.
I continue to have increased vigilance looking for this organism, as it is associated with significant morbidity and even mortality if treatment is delayed. It is very important to have cultures as soon as possible.
If there is any open wound, a wound swab can be sent for gram stain. Consider an incision through an area of redness and tenderness (if streptococcus is being considered ) with a biopsy of a deeper tissue plane for gram stain/culture.
In some circumstances, consider an aspiration for gram stain after saline injection to obtain a diagnostic sample. Once you know the bacteria, the treatment plan follows.
Additional investigations can be helpful. An elevated white blood cell count consistent with infection, imaging with ultrasound, or MRI can point to an infection. It is important though to remember that with this organism, you will not see gas in the soft tissues.
When called about a potential patient (unstable), alerting our OR and ICU with regards to the potential for emergent surgery and medical support is part of our protocol when we feel that this diagnosis is likely.
Having all the resources mobilized in advance is appreciated by your colleagues and hospital.