Primary closure vs second-intention treatment of skin punch biopsy sites: a randomized trial.

OBJECTIVE To determine if healing of punch biopsy wounds by second intention is equivalent to healing with primary closure. DESIGN Prospective, randomized, method comparison equivalence study. SETTING Tertiary academic medical center. PARTICIPANTS Study volunteers were recruited from the general population and enrolled between January 7, 2002, and August 20, 2002. Patients with immunodeficiency, peripheral vascular disease, or history of keloid formation and those receiving anticoagulation therapy or systemic corticosteroids were excluded. Intervention Study volunteers had two 4-mm or two 8-mm punch biopsies performed on the upper outer arms, midlateral aspect of the thighs, or upper back. One biopsy site was closed with interrupted 4-0 nylon suture, and the contralateral biopsy site was allowed to heal by second intention. MAIN OUTCOME MEASURES At 9 months, scar appearance was evaluated blindly and independently by 3 physicians using a visual analog scale (0 indicating poor and 100 indicating best). RESULTS Seventy-seven of 82 enrolled volunteers completed the study. Mean (SD) visual analog scale score was 57.1 (19.5) for biopsy sites allowed to heal by second intention and 58.9 (19.7) for biopsy sites that healed with primary closure. The median surface area of the biopsy scars at 9 months was 32 mm(2) for second intention and 33 mm(2) for primary closure. For the 8-mm biopsies, the volunteers preferred the appearance of the sites that healed with primary closure; however, for the 4-mm biopsies, volunteers had no significant preference for either biopsy method. Costs were lower for second intention, and complications were equivalent. CONCLUSIONS Punch biopsy sites allowed to heal by second intention appear at least as good as biopsy sites closed primarily with suture. Although volunteers preferred suturing at larger biopsy sites, elimination of suturing of punch biopsy wounds would result in personnel efficiency and economic savings for both patients and medical institutions.