Introduction: Postoperative surgical site infections are the most common complication following dermatologic surgery. The microbiology of these infections as it relates to patient and surgical characteristics is not well discussed.

Methods: A retrospective chart review on all patients with clinical evidence of wound infection and positive wound culture between 2011-2020 was performed at our tertiary care institution. The microbiology and resistance patterns were investigated in association with patient and surgical characteristics.

Results: Anatomic location was most stronly associated with the type of bacteria cultured, and contributed to the associations between specific bacteria and type of repair (linear, flap, graft) as well as suture material. There was no association between the bacteria cultured and whether the patient was immunosuppressed, smoking, anticoagulated, or diabetic. There was no association between the bacteria cultured and suture technique or procedure type (Mohs micrographic surgery vs excision vs biopsy vs electrodessication and curettage).

Conclusions: Understanding the microbiology of postoperative infections can help dermatologic surgeons in determining the best antibiotic regimen for treatment of these infections. Our study shows that anatomic location is the most important determinant of the type of pathogenic bacteria that will be cultured in a postoperative infection, and thus modifications on antibiotic based on the anatomic location of a surgical site.