Think you know everything about the lowly abscess? Think again. New research suggests you might want to use ultrasound before you lance, and suture before you pack.
After evaluating this article, participants will be able to:
1. Improve diagnostic accuracy for subcutaneous abscess
2. Incorporate a rational approach to the aftercare of abscess management
While I can already sense the yawns coming for this topic, stick with me for a moment. Believe it or not, there is some relatively recent information available on abscesses that will hopefully change some common practices.
First of all, I’m sure I’m not the only person who has lanced an “abscess” only to find that there is no puss pocket. What an embarrassment (although the patients may be oblivious to what the goal of the endeavor was). You’ve made a good size incision and have come up with nothing. Now what? Fill the hole with some packing, put a dressing on and give some antibiotics? You’ve needlessly done a procedure that has not benefited the patient, for which a scar will be left and for which an unnecessary charge will be generated.
The fact is that although some puss-filled abscesses can be diagnosed across the room, there is a subset in which it is difficult to distinguish between an abscess and cellulitis. Here’s a paper that I found a little discouraging (and which helps defend the need to more objectively determine if drainage will be rewarding). Pairs of pediatric ED attendings, fellows and pediatricians were asked to look at 371 pediatric skin infections and indicate whether the skin lesion was an abscess or a cellulitis. Pretty straight forward. The goal of the study was to see whether they agreed on the diagnosis. Agreement was only “fair” as to abscess vs. cellulitis and “moderate” as to whether there was a need for drainage. The conclusion – more objective methods of assessment are needed.
RELIABILITY OF CLINICAL EXAMINATIONS FOR PEDIATRIC SKIN AND SOFT TISSUE INFECTIONS
Marin, J.R., et al, Pediatrics 126(5):925, November 2010
BACKGROUND: Presentation to the ED of patients with skin and soft tissue infections increased nearly three-fold nationally from 1993 to 2005. Clinical differentiation of abscesses which should undergo drainage procedures from cellulitis which is treated with systemic antibiotics can be difficult. Studies of patients with other conditions have reported substantial variability in physicians’ clinical impressions.
METHODS: In this study, from the Children’s Hospital of Philadelphia, 371 skin lesions in 349 children aged 2 months to 19 years presenting to the ED of an urban tertiary care pediatric hospital were independently examined by two physicians, and the agreement between the examiners regarding the presence or absence of an abscess and the need for drainage was determined. The study involved 62 pediatric emergency medicine attending physicians or fellows, and pediatricians without formal pediatric emergency medicine training.
RESULTS: There was only fair agreement between the examiners regarding the presence of an abscess (kappa=0.39). and moderate agreement regarding the need for drainage (kappa=0.43). Agreement regarding the need for drainage was more likely for patients aged four years or older than for younger patients (relative risk 1.24), but levels of agreement were not influenced by patient race (black vs. non-black), a history of, or exposure to, a close contact with a skin/soft tissue infection, or level of experience of the physician examiners (three or more years vs. less experience).
CONCLUSIONS: These findings are consistent with poor reliability of the clinical diagnosis of skin and soft tissue infections among pediatric emergency medicine physicians, and demonstrate the importance of identifying effective methods of diagnosing these infections. 18 references (email@example.com – no reprints)
Copyright 2011 by Emergency Medical Abstracts – All Rights Reserved 4/11 – #9
In steps ultrasonography to the rescue. Not that I know how to do it, but I’ve read that even old guys like me can learn in about 30 minutes to quickly determine if there is a puss pocket worth going after in suspected abscesses. The most impressive paper on this approach that I have seen recently came from Carolinas Medical Center. The title is a little misleading because the study included both cellulitis and abscesses – two conditions that I think are different. In any case, patient management was changed in 56% of the cases as the result of performing an ultrasound exam – 48% not thought to need drainage needed one and 73% thought to need drainage didn’t – a definite practice changer!
THE EFFECT OF SOFT TISSUE ULTRASOUND ON THE MANAGEMENT OF CELLULITIS IN THE EMERGENCY DEPARTMENT
Tayal, V.S., et al, Acad Emerg Med 13(4):384, April 2006
BACKGROUND: The clinical identification of an abscess requiring drainage can be difficult in patients presenting with soft tissue infections.
METHODS: In this prospective study, from Carolinas Medical Center in Charlotte, NC, 126 patients aged 18-90 (average, 42) presenting to the ED with evidence of cutaneous soft tissue infections without obvious signs of an abscess underwent soft tissue ultrasonography (US) performed by one of five ED physicians experienced in ultrasonography. Physicians managing the patients were requested to provide their pre-test probability of a subcutaneous fluid collection and the need for a drainage procedure.
RESULTS: Soft tissue ultrasonography was consistent with a fluid collection typical of an abscess in 50% of the patients and drainage procedures were performed in 58 of these 63 patients. The accuracy of the managing physicians’ pre-test probability of a subcutaneous fluid collection ranged from 56% when the pre-test probability cut- off was 10% to 51% when the cut-off was 90%. Patient management was changed on the basis of ultrasound findings in 56% of the patients, including 48% of those not believed to require a drainage procedure based on clinical assessment and 73% of those felt to require drainage based on clinical evaluation (drainage was no longer felt to be necessary in half of these latter patients and the remaining patients were felt to require further tests, consultations, etc.).
CONCLUSIONS: Management was changed on the basis of soft tissue ultrasonography in about half of these ED patients with cutaneous soft tissue infections without a clinically obvious abscess. 15 references (firstname.lastname@example.org)
Copyright 2006 by Emergency Medical Abstracts – All Rights Reserved 8/06 – #20
OK. You found the puss and have drained it. What next? To my thinking, packing is cruel and unusual punishment, especially when you advise that the patient be repacked in several days (usually without the benefit of any anesthetics, which was at least present during the first packing). Not to mention the poor colleague who will be given the nasty task.
So what’s the idea of stuffing that hole full of some kind of impregnated gauze? And the word packing seems to imply, at least to some, that the idea is to pack the stuff in nice and tight. I used to envision packing as some sort of ladder that the white blood cells would use to climb out of the abscess with
their bacterial victims. Not anymore.
Although a number of anti-packing studies are out there, here is a relatively recent one. It is small but makes the point. At blinded follow-up at 48 hours there were no differences noted in packed vs non-packed abscesses. Outcomes were the same and patients without packing used 30% fewer doses of analgesics. As an aside, 60% were caused by MRSA and all received TMP-SMZ (which purist may say tainted the study. Not me).
ROUTINE PACKING OF SIMPLE CUTANEOUS ABSCESSES IS PAINFUL AND PROBABLY UNNECESSARY
O’Malley, G.F., et al, Acad Emerg Med 16(5):470, May 2009
BACKGROUND: Although the management of a cutaneous abscess following incision and drainage (I&D) traditionally includes packing, there is no clear evidence to support this practice, which is painful and may lead to additional healthcare visits.
METHODS: In this study, from Albert Einstein Medical Center in Philadelphia, 48 generally healthy adults with a cutaneous abscess not larger than 5cm in diameter on the trunk or extremity that was felt to require I&D but not IV antibiotics were randomized to packing with 1/4-inch non- iodophor impregnated gauze or to no packing after I&D. All patients received a prescription for trimethoprim-sulfamethoxazole plus an analgesic.
RESULTS: The wound culture was positive for MRSA in 60% of the patients. On 48-hour follow-up (available for two-thirds of the patients) by a physician blinded to initial study group, there were no differences between the groups in the need for additional intervention. Telephone follow-up was available for ten of eleven patients from the no-packing group who did not return at 48 hours; all ten reported no pain, and stated that they did not feel that the abscess required follow-up. Of the three patients randomized to packing who did not return at 48 hours, the one with available telephone follow-up reported moderate pain (50 on a 100mm scale). None of the 36 patients who were contacted at 10-15 days reported complications. Patients randomized to no packing reported less pain after the procedure and at 48 hours than those randomized to packing, and used about 30% fewer doses of ibuprofen or codeine/acetaminophen.
CONCLUSIONS: Findings in this small study suggest that routine packing after I&D of a cutaneous abscess is painful and does not appear to be beneficial. 4 references (email@example.com for reprints)
Copyright 2009 by Emergency Medical Abstracts – All Rights Reserved 10/09 – #11
Although packing is probably not useful, there’s nothing to say that inserting a small Penrose type drain to help keep the edges from adhering isn’t a bad idea. But want to get radical? What about suturing the abscess closed after drainage. It’s certainly not the U.S. standard, but Adam Singer recently did a meta-analysis of seven studies of the topic and found some really interesting stats. The studies were old (the newest 2001), more than half were anogenital and most studies were prior to the MRSA era. Healing time was 8 days with suturing vs. 15 without; return to work was 4 vs 15 days, the complication rate with suturing was less that without (8% vs 11%), fewer recurrences occurred with suturing and good quality scars were more common (90% vs 29%).
PRIMARY CLOSURE OF CUTANEOUS ABSCESSES: A SYSTEMATIC REVIEW
Singer, A.J., et al, Am J Emerg Med 29(4):361, May 2011
BACKGROUND: The traditional approach to the management of a cutaneous abscess consists of incision and drainage (I&D) followed by secondary healing via granulation and reepithelialization. Several studies have reported that primary closure after I&D might be associated with greater improvement in selected outcomes.
METHODS: The authors, from Stony Brook (NY) University, performed a meta-analysis of seven randomized controlled trials (915 patients in four countries, between 1976-2001) comparing primary and secondary closure after I&D of a cutaneous abscess.
RESULTS:. Six of the seven studies were published prior to 2000, before the pronounced increase in community-associated methicillin-resistant S. aureus (CA-MRSA). More than half of the abscesses involved the anogenital region. The mean healing time was 7.8 days with primary suture closure vs. 15.0 days with secondary closure, and the mean times to return to work were 4.1 vs. 14.6 days, respectively. The mean complication rate was 8.1% in patients randomized to primary suture closure vs. 11.0% in those randomized to secondary closure, and mean rates of abscess recurrence were 7.6% vs. 11.1%, respectively. One study that assessed appearance of the wound after three months reported a “good” quality scar in 90% of patients randomized to primary suture closure vs. 29% of those randomized to secondary closure.
CONCLUSIONS: In these patients, primary suture closure after I&D of a cutaneous abscess was associated with more rapid healing and a lower rate of abscess recurrence than was secondary closure. However, these study subjects do not seem to be representative of most current ED patients, so the findings should be interpreted with caution. 23 references (firstname.lastname@example.org – no reprints)
Copyright 2011 by Emergency Medical Abstracts – All Rights Reserved 11/11 – #9
In one impressive study, use of ultrasound in suspected abscesses caused a change in management 56% of the time. 48% not thought to need drainage needed it, and 73% thought to need drainage didn’t.
Richard Bukata, MD is Editor of Emergency Medical Abstracts (www.ccme.org)