New practice guidelines on skin and soft tissue infections from the Infectious Diseases Society of America stress careful clinical attention to the type of infection, the epidemiological setting in which the infection occurred, the health status of the patient, and the selection and dosage of the most appropriate treatment agents.
The guidelines, published online June 18 in Clinical Infectious Diseases (doi:10.1093/cid/ciu296), update those issued by IDSA in 2005 and cover everything from preventing infections caused by animal bites in healthy hosts to life-threatening infections in immunocompromised patients. They also emphasize accurate identification of pathogens, stressing that clinical presentations can be very similar.
"This is not one of those guidelines that boils complex issues down to a choice between a couple of different drugs or combinations of drugs," said Dr. Dennis Stevens of the Department of Veterans Affairs in Boise, Idaho, the guidelines’ lead author. "Skin and soft tissue infections [SSTIs] have multiple causes and different presentations, depending upon the immune status of the host. Here it’s much more complicated and really requires an astute physician to consider a number of things."
The guidelines, drafted by a 10-member panel, offer a novel algorithm for management of nonpurulent and purulent infections that aims to define a pathway for mild, moderate, and severe infections in each category. For example, no antibiotic is recommended for a purulent infection – only incision and drainage – if the patient has no signs of systemic involvement.
For moderate cases of purulent infection with some systemic involvement, incision and drainage should be followed by culture and sensitivity testing, the guidelines say, listing two antibiotics, trimethoprim-sulfamethoxazole and doxycycline, as appropriate for empiric treatment, while trimethoprim-sulfamethoxazole is recommended if the pathogen is found to be methicillin-resistant Staphylococcus aureus (MRSA) and dicloxacillin or cephalexin if it is methicillin-susceptible S. aureus (MSSA).
The purpose of the algorithm, expressed in the guidelines in chart form, "is to make the physician think," Dr. Stevens said in an interview. "There is a huge move to try and monitor antibiotic stewardship to prevent resistance, and we’re just trying to get the clinician to think of tier 1, tier 2, and tier 3 approaches, depending not only on the bug, but on how sick the patient is. Instead of a knee-jerk approach treating everybody with highly expensive IV antibiotics, [the algorithm] provides a clear pathway to treat appropriately."
In people with an abscess who have failed antibiotic treatment, are immunocompromised, or have fever and elevated white blood cell counts or other evidence of severe infection, "we’re not going to gamble," Dr. Stevens said, adding that the guidelines recommend prompt treatment using "an antibiotic that gets all of these organisms, including resistant ones." Newly approved agents dalbavancin and tedizolid are effective in treating SSTIs caused by MRSA, the guidelines note.
The guidelines are intended for use by clinicians in emergency departments, family practice, internal medicine, general surgery, orthopedics, gynecology, dermatology, infectious disease, and oncology.
Another algorithm charted in the guidelines covers wound infections following surgeries, which can involve multiple pathogens. The algorithm provides simple clinical clues as to which require antibiotics, a simple opening of the suture line, "or a full-court press for the kind of devastating infections that occur within the first 48 hours," Dr. Stevens said. Additional recommendations address infections that can occur in individuals receiving treatment for cancer or receiving immunosuppressant medications, or those who have had an organ transplant or who have HIV/AIDS.
Immunocompromised patients, Dr. Stevens said, are among the most challenging to treat because they may have a history of extensive antibiotic exposure, are likely to have infections with resistant bacteria, and often see involvement with fungal and parasitic agents that might be considered innocuous in normal individuals. "This is the first time physicians will have some decent guidelines about how to approach the problem of skin and soft tissue infections in these kinds of patients," he noted.
The guidelines’ development was funded by the IDSA. Dr. Stevens reported no conflicts of interest. Panel member Alan L. Bisno disclosed receiving honoraria from UpToDate, while five other members – Dr. Henry F. Chambers, Dr. E. Patchen Dellinger, Dr. Ellie J. C. Goldstein, Dr. Sherwood L. Gorbach, and Dr. Sheldon L. Kaplan – disclosed financial relationships with pharmaceutical manufacturers.