“I incised and drained the abscess; it should have done well.”Avoid making assumptions and provide all patients treated in the ED with follow-up. In the majority of patients with an abscess, incision and drainage without the addition of antibiotics is sufficient; however, exceptions do occur, and follow-up is key to early recognition. Of particular note, patients with comorbidities such as diabetes mellitus are at increased risk for complications, and clear instructions on when to follow up should be a critical component of their care.
“I incised and drained the abscess. That should have been sufficient.”It is sufficient only if it is done correctly. Inadequate incision and drainage is the most common cause of treatment failure. All abscesses require careful exploration for loculations, which must be treated so the infection can drain properly. Failure to open loculations places the patient at risk for progression of the infection.
“I thought it was just a cellulitis.”Deep abscesses can be difficult to identify. The advent of bedside ultrasound in the ED has provided a new tool for avoiding misdiagnosis. Ultrasound should be used liberally in patients with cellulitis since the infection will not be treated unless the abscesses are drained.
“The patient had a cellulitis, and since I was concerned about MRSA, I treated it with TMPSMX.”MRSA is a concern in patients with a cellulitis complicating an abscess; however, in an uncomplicated cellulitis, S pyogenes is still the most common organism and it is not treated with TMP-SMX. In this patient, a first-generation cephalosporin would have been a better choice.
“I didn’t cover for MRSA because the patient didn’t have any high-risk factors.”CA-MRSA is the most frequently isolated pathogen from SSTI in the ED. Two studies have demonstrated that risk factors and clinical judgment are unreliable at distinguishing between MSSA and CA-MRSA.
“The patient was just released from the hospital so I suspected MRSA and treated with TMP-SMX.”HA-MRSA is very different from CA-MRSA; it has a multi-resistant pattern and requires aggressive coverage with vancomycin or linezolid.
“The patient had a lesion on his ankle; we were so busy and the ED was so crowded, I didn’t undress him.”Too bad for the patient – the cellulitis extended up the leg and was associated with crepitus, hemorrhage, and blistering. The patient was sent home on oral antibiotics and returned within 12 hours, septic.
“I never send cultures on the abscesses I drain. It’s too expensive.”A complicated abscess requiring hospitalization should be cultured, because the results may ultimately alter the patient’s management, but sending cultures routinely for all simple abscesses is controversial.
“I thought it was just a bad case of communityacquired pneumonia.”Turns out, it was a really bad case and the patient died. CA-MRSA CAP has a high mortality and should be considered in any patient presenting during an influenza outbreak or with a preceding flulike illness and rapid progression to severe illness.
“The patient was allergic to TMP-SMX and the cultures showed MRSA sensitive to rifampin, so it seemed like a good choice.”Seeming like a good choice and being a good choice are two different things! Although CAMRSA often demonstrates susceptibility to rifampin in vitro, resistance develops rapidly during treatment, so it should never be used alone.