Zinc Oxide Versus Petrolatum Following Skin Surgery: A Head-to-head, Prospective, Split-scar Study

Patients who have undergone dermatologic excision for any indication with or without Mohs micrographic surgical technique and surgically closed in linear fashion with scar length of greater than or equal to 4.5cm on any site but the scalp will be approached for enrollment in the study. Any closure in which one half of the linear scar appears grossly unequal to or worse than the other (due to any number of causes, such as suture technique, etc.) will be excluded from the study. Any patient whose surgical procedure was deemed as having high risk of post-surgical infection would also be excluded from the study as well as those with known history of topical zinc allergy. Consent will be obtained with one of the trained co-investigators. Included in this consent will be consent to collection of basic patient medical data pertinent to wound healing/scar formation will be obtained, such as history of keloids, smoking, history of diabetes mellitus, history of cancer and/or on chemotherapy, history of transplant, and immunosuppressive status, etc. for the purposes of this research. Risk to patients using zinc oxide ointment has been deemed by the FDA as minimal. Of note, zinc oxide ointment currently is the gold standard treatment for erosive diaper dermatitis on newborns and infants. It is generally deemed safe clinically and its application to other clinical settings outside of diaper rash has not been explored.

Upon providing consent for the study, the patient's surgical closure will be demarcated with sterile inked pen and "V" will be drawn on one end and "Z" on the other. The control, standard of care petrolatum (i.e. Vaseline) will be applied to the side indicated by "V" and the experimental treatment zinc oxide will be applied to the "Z" side. As a general rule, if oriented longitudinally, "Z" will mark distal, "V" will mark proximal. If oriented horizontally (left to right), "V" will mark the left side, "Z" the right. The ointments and standard pressure dressing will be administered in clinic upon closure and consent/enrollment. Patients will be sent home with package containing standard wound dressing materials as well as both zinc oxide and petrolatum.

Patients will be sent home with instructions and wound care materials to perform the following: (1) Keep post surgical pressure dressing in place for 48 hours (2) Gentle soap and water cleansing after 48 hours once daily (3) With daily dressing changes self apply zinc oxide ointment to side indicated by "Z" and petrolatum (vaseline) to side indicated by "V" (3b) Patient will be encouraged to re-mark site Z and V to serve as reminder to enhance compliance (4) Patient will sign off on daily log twice: once upon application of zinc oxide to Z side and upon application of petrolatum to V side. (5) Patient will perform daily dressing changes as above for one month. The application of daily ointment with or without dressing is also routine standard of care at the present time. Draft of patient instructions has been included with this submission.

Patients will be seen at the routine standard of care visit 7 days post-op for suture removal. At this point in time, accompanying dressing will be taken down, cleansed with sterile saline, and patient wounds will be photographed under standardized conditions, with avoidance of any clue as to which ointment was applied to which side. In addition, patients will perform the patient portion of the POSAS (Patient and Observer Scar Assessment Scale v2.0, a validated measure of scar cosmesis, with 6 to 60 scale, with low numbers represent that scar appears most similar to normal skin, whereas 60 indicates that the scar is visually furthest from normal skin, i.e. worst possible scar). Patients will also follow-up at 4 weeks, 8 weeks, and 6 months post-operatively for scar assessment. Patient parking will be validated. For patients requesting optimal close clinical follow-up for post-surgical scars, this appointment schedule represents the highest standard of care. At these visits, photographs will be obtained, and patients will again be asked to complete the patient portion of the POSAS scale. Upon completion of the six month follow-up visit for this pilot study, patients will be given a basic skin care product sample gift bag, containing a standardized collection of samples of hypoallergenic washes and moisturizers. Of note, if a patient is unable to return for the final six month follow-up visit, patients will be allowed to submit electronic photographs (non-standardized, self taken) with clear instructions to send via secure message via MyUPMC, a secure interface allowing for communication between patient's and doctors within the UPMC (University of Pittsburgh Medical Center) network. This option is to be reserved as a last resort. Patients will not receive the gift bag if unable to return for this final study visit. Please note that patient obtained and entered photographs are routinely used clinically for remote assessment of skin disorders for routine clinical follow-up.

Board-certified dermatologists at the end of the study will evaluate the photographs obtained at a later point in the study. Through photographic and/or edited technique if necessary, they will be blinded to which side received zinc oxide and which side received petrolatum. Indeed, the POSAS has been validated with photographic use. In addition, an estimation of the linear proportion of epidermal seal will be evaluated visually based on clinical exam and/or photographs. Specifically, the length of the wound will be measured at this visit and distance of scar containing non grossly apposed skin edges will be measured. The sum of length of non-sealed areas within the V side and within the Z side will be calculated. In addition, clinical evidence of surgical site infection, wound disruption, and/or any other post-surgical complications will be documented.