The incidence of skin abscess, always a common diagnosis in the ED, is increasing in this era of methicillin-resistant Staphylococcus aureus (MRSA). (Ann Emerg Med 2008;51:291.) The standard of care for uncomplicated skin abscess, despite limited evidence, has been incision and drainage, followed by placing loose gauze packing with serial dressing changes until healing is complete (secondary closure). (N Engl J Med 2007;357:e20.)
Unfortunately, I&D with packing is one of the most painful ED procedures reported by patients. (Ann Emerg Med 1999;33:652.) Post-procedure wound care can also be painful, inconvenient, and costly, and can result in slow wound healing or poor cosmesis. Not surprisingly, many alternative approaches have been suggested.
Ultrasound-guided needle aspiration, for one, would seem to be a much less invasive approach to I&D, but this technique has shown to be significantly less successful and even less likely to work if MRSA is the causative organism. (Ann Emerg Med 2011;57:483.) Others advocate minimally invasive incisions with placement of a loop drain, which has shown promise in the operating room and inpatient settings. Successful use in the ED, however, has not yet been established. (J Pediatr Surg 2010;45:606.)
Some studies have shown no clear benefit to gauze packing after I&D if the abscess is small and simple. (Pediatr Emerg Care 2012;28:514.) Even the guidelines from the Infectious Diseases Society of America suggest that I&D without packing is preferable in selected cases. (Clin Infect Dis 2005;41:1373.) Other studies have looked at I&D with alternative packing, and compared with traditional iodoform strips, silver-containing hydrofiber packing may be left in place longer, and may result in more rapid healing with less pain. (Adv Skin Wound Care 2013;26:20.)
Suturing the I&D site after abscess drainage could potentially save a patient the time, trouble, cost, and pain associated with many of these options, but primary closure of an infected wound is generally contraindicated. A recent systematic review, however, has challenged this belief by showing that primary closure could result in more rapid healing without compromising recurrence rate. (Am J Emerg Med 2011;29:361.) Many of these abscesses in this study, however, were confined to the anogenital region and drained under general anesthesia by surgeons in the operating room.
This month's Journal Scan examines a new study evaluating primary closure of skin abscesses drained in the ED setting.
Primary vs. Secondary Closure of Cutaneous Abscesses in the Emergency Department: A Randomized Controlled Trial
Singer AJ, Taira BR, et al
Acad Emerg Med
This prospective, randomized, controlled trial was designed to determine whether primary closure after I&D of simple skin abscesses drained in the ED is superior to the common practice of I&D with gauze packing. The authors hypothesized that primary closure would result in faster healing without increasing failure rate.
The study was conducted in two academic EDs, one urban and one suburban. Patients were excluded if they had significant surrounding cellulitis (>5 cm), immune compromise, or endocarditis risks, if they required procedural sedation or general anesthesia, or if they exhibited any systemic signs of infection.
The actual incision was standardized in each arm as much as possible. Vertical mattress sutures (4-0 monofilament) were used in the primary closure group to approximate the skin edges together without any packing or wick placement. The control group received the more traditional intervention of loose packing with saturated iodoform gauze strips to allow healing by secondary intention.
Follow-up wound assessment was completed at 48 hours, and the primary outcome — wound healing — was assessed at seven days. One of the secondary outcomes — overall treatment failure — was defined by the need for any additional intervention including early suture removal, additional incision, new antibiotics, or hospital admission.
A total of 56 patients were enrolled in the study, and their abscesses were located on the head and neck (23.2%), axilla (23.2%), extremities (19.6%), trunk (17.8%), and buttocks (14.3%). Antibiotics, prescribed under the discretion of the treating physician, were given in 30.8 percent of the study group and in 41.4 percent of the control group.
No statistical difference was found in healing between the groups at seven days: 69.6 percent for primary closure and 59.3 percent for secondary closure. Overall treatment failure was also not statistically significant between the two groups.
Primary closure was not found to be superior to the more familiar strategy of packing and wick placement. The authors speculate that this unexpected result was partly because of the overall small size of the enrolled abscesses and the short incisions used in the study. They theorized that primary closure might result in superior healing for larger abscesses requiring longer incisions.
Yet, even if these two treatments were found to be equally successful, perhaps other benefits exist to suturing the abscess closed after I&D. First, patients might prefer having sutures placed to forego the need for daily wound care and dressing changes. This study found no difference in patient preference between the two groups. Sutures might also minimize scar formation. The authors chose to place vertical mattress sutures in the study group because they thought they might better obliterate a deep abscess cavity. Vertical mattress sutures, however, are also more technically difficult and time-consuming to place, and have been associated with more “railroad mark” surface scarring. (Am Fam Physician 2002;66:2231.)
Prior studies have granted surgeons license to close abscesses primarily under specific settings. Primary closure, however, should not be used in the ED to treat skin abscesses drained anywhere on the body based on this study. Standard practice of leaving I&D sites open should not change. Secondary closure, with or without gauze packing, should remain our primary option, until a more viable option is found.
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