Abscesses are one of the most common skin conditions encountered by general practitioners and emergency physicians, and the incidence of these infections has increased in recent years. In addition, MRSA infections have become one of the most common causes of skin abscesses. “Community-associated MRSA (CA-MRSA) has also been shown to cause severe infections in non-immuno-compromised hosts,” explains David A. Talan, MD, FACEP, FIDSA. “We’re still unsure as to why CA-MRSA appears to be more virulent than other healthcare–associated strains and methicillin-susceptible Staphylo-coccus aureus. Unfortunately, the management of skin abscesses is highly variable throughout the country.”

In a review article published in the New England Journal of Medicine, Dr. Talan and Adam J. Singer, MD, described helpful approaches to managing common skin abscesses that generally involve the extremities and trunk. “When possible, our recommendations were based on randomized trials,” Dr. Talan says. “However, many recommendations are based on small observational studies or expert opinion. While there may be some disagreement, the approaches we advise have been both workable and useful in our practice.”

Diagnosis

Skin abscesses typically appear as a swollen, red, tender, and fluctuant mass, often with surrounding cellulitis. The diagnosis of skin abscesses based on physical exams is often straightforward and proven correct by incision and drainage. Ultrasonography may be helpful for cases in which the abscess is deep, complex, or obscured by extensive cellulitis. It may also be helpful for patients treated for cellulitis in which initial antibiotic treatment fails and to ensure the adequacy of drainage. Needle aspiration is an alternative approach to diagnosing and treating abscesses.

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Treatments

“Standard incision and drainage is the mainstay of managing abscesses,” says Dr. Talan. “Over time, clinicians have improved techniques for draining abscesses so that patients experience less pain and discomfort. Alternative drainage techniques have been investigated, but most abscesses can typically be drained with a single small incision.” He adds that systemic antibiotics should be given to patients with systemic signs of infection. Routine irrigation and packing of abscesses may be unnecessary, based on clinical studies. Smaller incisions with loop drains and primary closure are other options to consider in select cases.

The Infectious Diseases Society of America (IDSA) recommends systemic antibiotic treatment—in addition to incision and drainage—for patients with severe or extensive disease or with rapid disease progression and associated cellulitis. The IDSA also recommends this approach for patients with:

“Whether adjunctive antibiotics are generally helpful for patients with drained skin abscesses will soon be addressed in studies we are completing,” Dr. Talan says. Empirical antibiotic therapy, if prescribed, should demonstrate activity against CA-MRSA. Most patients with minor abscesses can be treated as outpatients with inexpensive oral antibiotics, with studies showing that these drugs have activity against 94% to nearly 100% of more than 300 MRSA isolates. The IDSA has issued recommended doses of these anti-biotics (Table 1).

Other antibiotics for MRSA have been approved by the FDA for skin and soft-tissue infections, including vancomycin, linezolid, daptomycin, telavancin, tigecycline, and ceftaroline. However, resistance has emerged to some of these agents in some communities. “This means that clinicians should be aware of local susceptibility patterns,” says Dr. Talan. Wound cultures can also be considered but limited to severe cases, immunocompromised patients, and those in whom initial therapy is failing.

Prevention

Some people are particularly prone to recurrent skin abscesses. Decolonizing index patients and household contacts may help prevent recurrent infections. A 5-day regimen of hygiene, nasal mupirocin treatment, and chlorhexidine body washes has been recommended for patients with recurrent infections who are colonized with MRSA at any site, but this course of treatment is rigorous and will require highly motivated patients to complete this approach (Table 2).

“Even with optimal treatment, short-term failures do occur, and new lesions can still develop,” says Dr. Talan. “As such, it’s critical to educate patients about ways to prevent these infections and to follow up with them appropriately.” Dr. Talan adds that studies are underway to further improve management strategies for CA-MRSA in skin- and soft-tissue abscesses. Dr. Talan says, “We hope this research will provide the answers we need to better treat patients with these infections and ultimately help us improve cure rates while reducing recurrent disease.”

References

Singer AJ, Talan DA. Management of skin abscesses in the era of methicillin-resistant Staphylococcus aureus. N Engl J Med. 2014;370:1039-1047. Available at: http://www.nejm.org/doi/full/10.1056/NEJMra1212788.

Liu C, Bayer A, Cosgrove SE, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis. 2011;52:e18-e55.

Talan DA. Lack of antibiotic efficacy for simple abscesses: have matters come to a head? Ann Emerg Med. 2010;55:412-414.

Fritz SA, Hogan PG, Hayek G, et al. Staphylococcus aureus colonization in children with community-associated Staphylococcus aureus skin infections and their household contacts. Arch Pediatr Adolesc Med. 2012;166:551-557.

Taira BR, Singer AJ, Thode HC Jr, Lee CC. National epidemiology of cutaneous abscesses: 1996 to 2005. Am J Emerg Med. 2009;27:289-292.