CHICAGO – Infections from dermatologic surgery are rare, but possible, especially in high-risk patients, such as the immunosuppressed and those with joint or cardiac prostheses.

“Data from the four largest studies on this topic suggest an infective bacteremia of about 1.9% associated with all derm surgeries, which is actually less than you see with normal daily activities, like brushing your teeth and flossing,” Christopher C. Gasbarre, D.O. said at the meeting . “Add to that the fact that the American Heart Association guidelines note that antibiotic prophylaxis doesn’t decrease the risk of infection to 0%,” and the decision of whether to give the drugs becomes problematic.

Patients who are at high risk of postoperative infections, however, should receive preoperative or immediately postoperative antibiotics, said Dr. Gasbarre, a dermatologist at the Cleveland Clinic. “It’s important to remember that infective endocarditis and prosthetic joint infections secondary to dermatologic surgery are a well-known phenomenon, and a distant skin infection is the leading cause of prosthetic joint infections.”

The American Heart Association reviewed and updated its surgical antibiotic guidelines in 2007, “making a significant shift in focus compared to their previous guidelines,” Dr. Gasbarre said. The guidelines now recommend prophylaxis for patients with any prosthetic implanted material including cardiac valve replacements; cardiac patients with valvular disease; those with a history of infective pericarditis; anyone with unrepaired cyanotic congenital heart disease or a defect repaired within the past 6 months; and any congenital heart disease with a residual defect.

The American Dental Association updated its surgical antibiotic guidelines recently as well. “The guidelines recommend prophylaxis for high-risk patients undergoing oral procedures with a high risk of bleeding,” he said.

Guidelines issued by the American Association of Orthopaedic Surgeons identify similar high-risk groups that should receive presurgical antibiotic therapy, including anyone who is less than 2 years out from a joint replacement, who is immunosuppressed, and who has hemophilia. “In dermatologic surgery, there are no studies on antibiotic prophylaxis, so we have to make do with these other recommendations,” Dr Gasbarre said.

Preventing wound infections is a major goal of surgical antibiotic treatment, he said. “In the dermatologic literature, the numbers range from 0.7% to %, depending on what study you’re looking at.”

Surgical site is a major consideration in anticipating postsurgical infections. “Ears, the nose, and lower leg below the knee have a greater risk of infection. Flaps and grafts have a higher risk, especially flaps on the nose. And a major cosmetic reconstruction that results in necrosis and scarring should also be a consideration.”

The Mayo Clinic’s 2008 surgical antibiotic prophylaxis guidelines suggest antibiotics for dermatologic surgeries of the lower extremities, groin, and perineum; wedge excisions of the lip or ear; and other procedures with reported infection rates of at least 5%. Again, patients with immunosuppression require specific attention, as do those with inflammatory skin diseases, “who may carry a higher staphylococcus load on the skin,” Dr. Gasbarre said.

The literature suggests other high-risk groups might be those who undergo several procedures in 1 day, have high-tension wound closures, and have surgery on the hands, he added.

“The one thing that gets the most debate is whether to give antibiotics for a wound that’s exposed more than 3 hours, Dr. Gasbarre said. “I often do, although there are no guidelines. I take into consideration comorbidities, but certainly any surgery of the nasal mucosa and long procedures are worthy of consideration.”

Culture is important for high-risk patients. “Culture for both community- and hospital-acquired methicillin-resistant Staphylococcus aureus and jump on those infections and eradicate them as quickly as possible.”

Timing is another consideration. “Ideally we give antibiotics 30-60 minutes before the procedure to get enough antibiotic in the coagulum. But the new AHA guidelines say you can give them up to 2 hours after the procedure if not given before.”

Select antibiotics carefully. “Beta hemolytic streptococcus and S. aureus are most likely to cause endocarditis from skin sites. You see a lot of gram-negative infections in the lower extremities and perineum. Pseudomonas can show up in the ear, but more than 90% of cultured ear isolates are staph and strep, not pseudomonas.”

If the patient is not allergic to penicillin, Dr. Gasbarre prefers 2 g oral cephalexin or treatment with dicloxacillin or amoxicillin. “For oral mucosa, amoxicillin is the drug of choice. For patients who are allergic, I stick with 600 mg of clindamycin or 500 mg of azithromycin.”

Ciprofloxacin, trimethoprim, and levofloxacin are choice for the ear, groin, and lower extremities.

“If patients can’t take anything orally, ceftriaxone 1 g given intramuscularly or intravenously is acceptable, with or without gentamicin for gram-negative coverage,” Dr. Gasbarre said.

Dr. Gasbarre said he had no relevant financial conflicts.

Dermatologic Surgery Site Specifics Point to Antibiotic Choices