SAN DIEGO – The need for antibiotic prophylaxis in dermatologic surgery depends on the type of procedure, the patient, what infection you’re trying to keep at bay, and the type of wound, according to Tissa Hata, MD, professor of dermatology at the University of California, San Diego.
Among the many studies in the medical literature that have examined the use of antibiotics to prevent surgical site infections, one study published in 2006 has the largest number of patients to date, Dr. Hata said at a conference on superficial anatomy and cutaneous surgery sponsored by UCSD and Scripps Clinic. In the prospective study of wound infections in patients undergoing dermatologic surgery without prophylactic antibiotics, researchers in Australia prospectively examined 5,091 lesions, mostly nonmelanoma skin cancers, in 2,424 patients over the course of 3 years.
By procedure, the infection rate was highest for skin grafts (8.70%) and wedge excision of the lip or ear (8.57%), followed by skin flap repairs (2.94%), curettage (0.73%), and simple excision and closure (0.54%). By anatomic site, groin excisional surgery had the highest infection rate (10%), followed by surgical procedures below the knee (6.92%), while those performed on the face had a low rate (0.81%). “Based on their analysis, they suggest antibiotic prophylaxis for all procedures below the knee and groin, wedge excisions of the lip and ear, and all skin grafts,” Dr. Hata said.
In 2008, an advisory statement published in the Journal of the American Academy of Dermatology expanded the procedure location and techniques requiring antibiotic prophylaxis to include procedures on the nose and the lower extremity (especially the leg), and for patients with extensive inflammatory disease. According to the statement, in patients without a penicillin allergy, the suggested antibiotic prophylaxis regimen for wedge excision of the lip/ear, flaps on the nose, or all skin grafts include 2 g oral cephalexin or dicloxacillin. In patients with penicillin allergy, the recommended prophylaxis regimen for wedge excision of the lip/ear, flaps on the nose, or all skin grafts include 600 mg oral clindamycin or 500 mg oral azithromycin/clarithromycin.
In the statement, for patients with no penicillin allergy, the suggested prophylaxis regimen for lesions in the groin or on the lower extremities include 2 g oral cephalexin, 1 tablet of oral trimethoprim/sulfamethoxazole (TMP-SMX) DS, or 500 mg of levofloxacin. In patients with penicillin allergy, the recommended prophylaxis regimen for lesions on the groin and lower extremities is 1 tablet of TMP-SMX DS or 500 mg of levofloxacin.
In 2020, a meta-analysis of surgical site infections in patients undergoing Mohs surgery of the ear and nose found that there was no difference in infections in those locations whether patients received oral antibiotic prophylaxis or not. “But the researchers did not specify the type of closure, whether it was a graft or a flap closure,” Dr. Hata commented.
Endocarditis prophylaxis
Dr. Hata also discussed antibiotic recommendations for endocarditis prophylaxis, noting that the mortality rate from endocarditis is as high as 76%, and an estimated 40% of affected patients require heart valve replacement within 5-8 years. “But the good news is that fewer than 10 cases have been possibly linked to dermatologic procedures,” she said.
During outpatient dermatologic surgery, the incidence of bacteremia is in the range of 1.9%-3%, similar to the incidence of 2% that occurs spontaneously in healthy adults, according to Dr. Hata. She said that the following activities or procedures pose a much higher risk of bacteremia: mastication (17%-24%), tooth brushing (24%-40%), tooth extraction (60%-90%), and incision and drainage of an abscess (38%).
American Heart Association guidelines from 2007 recommend antibiotic prophylaxis in only the highest-risk categories of patients. These guidelines were updated in 2017 to include patients with transcatheter prosthetic valves and those with prosthetic material in valve repair. “The primary reason for revision of guidelines is that endocarditis is much more likely to result from frequent exposure to random bacteremia associated with daily activity such as brushing our teeth or having a tooth extracted,” Dr. Hata explained. “Prophylaxis may prevent an exceedingly small number of cases. Authors of the guidelines concluded that the risk of antibiotic-associated adverse event exceeds the benefit of prophylactic therapy, and that maintenance of optimal oral health is more important than prophylactic antibiotics.”
The 2017 AHA guidelines recommend antibiotic prophylaxis in patients with the following cardiac conditions: those with a prosthetic cardiac valve including transcatheter-implanted prostheses and homografts; those with previous endocarditis; those with prosthetic material used for heart valve repair, such as annuloplasty rings, chords or clips; cardiac transplantation recipients who develop cardiac valvulopathy; and those with certain types of congenital heart disease, including unrepaired cyanotic CHD, a completely repaired congenital heart defect with a prosthetic material or device during the first 6 months after the procedure, and repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device.
Procedures that may require prophylaxis for endocarditis include all dental procedures that involve manipulation of the gingival tissue or the periapical region of teeth or perforation of the oral mucosa, and respiratory tract procedures that involve incision or biopsy of the respiratory mucosa such as tonsillectomy or adenoidectomy. Antibiotic prophylaxis is not recommended for procedures involving the gastrointestinal tract or the genitourinary tract unless an active infection is present. As for skin procedures, the guidelines recommend antibiotic prophylaxis for patients in the high-risk category who undergo a surgical procedure that involves infected skin, skin structure, or musculoskeletal tissue.
In the 2017 AHA guidelines, patients with no penicillin allergy, the suggested antibiotic prophylaxis regimen for endocarditis in non-oral sites includes 2 g oral cephalexin or dicloxacillin, while in patients with penicillin allergy, the suggested prophylaxis for endocarditis in non-oral sites includes 600 mg oral clindamycin or 500 mg oral azithromycin/clarithromycin. In patients without a penicillin allergy, the suggested prophylaxis for endocarditis in oral sites is 2 g oral amoxicillin, while in those with penicillin allergy, the suggested antibiotic prophylaxis for endocarditis in oral sites is 500 mg azithromycin/clarithromycin or doxycycline 100 mg.
“Antibiotic prophylaxis for endocarditis should be given 30-60 minutes prior to surgery, and a follow-up dose of antibiotics is no longer recommended,” Dr. Hata said. “If you forget [to administer the antibiotics] or the patient forgets, antibiotics may be given up to 2 hours after the procedure.”
Dr. Hata reported having no relevant disclosures.