Anesthetic blister induction to identify biopsy site prior to Mohs surgery.

BACKGROUND Wrong-site surgery in dermatology often occurs due to difficulty finding the initial biopsy site prior to Mohs surgery. Patients frequently present for Mohs surgery weeks to months following the initial biopsy site. Visualization of the biopsy site may become difficult at presentation due to healing. OBJECTIVE To investigate the utility of anesthetic blister induction at a suspected biopsy site to identify the location prior to Mohs surgery. The proposed technique is visualization of a blister that is induced by local anesthetic administration at the proposed biopsy site. The addition of this technique among others such as curettage, dermoscopy, and UV fluorescence can prevent wrong-site surgery. METHODS A biopsy site of a squamous cell carcinoma on a patient was compared via photography for visibility at the time of initial biopsy, weeks following biopsy, and post-anesthetic blister induction. RESULTS The biopsy site was easier to locate with the assistance of a blister that formed as a result of local anesthetic administration. CONCLUSION Blister induction by local anesthetic administration can assist in accurately identifying healed or obscured biopsy sites.