A reevaluation of the effect of occlusion on the trichloroacetic acid peel.

Background: Prior studies have demonstrated reduced wounding with trichloracetic acid (TCA) peels after tape occlusion. It is therefore reasonable to question whether or not other types of occlusion may have similar effects, particularly those used in routine postoperative care.
Objective: To reevaluate the effect of occlusion after TCA peels in multiple human models using various forms of dressings, at various times postoperatively, and to make recommendations regarding wound care that will not adversely affect the efficacy of the peel.
Methods: Equal-sized sections of anterior alopecic scalps of four patients were peeled with 50% TCA, occluded with bacitracin, Vigilon, or Tegaderm at various times postoperatively, and biopsied 1 day later. Depths of necrosis were measured and compared with nonoccluded controls.
Results: Bacitracin ointment and Vigilon did not lessen TCA wounding, and sometimes actually enhanced it. Conversely, Tegaderm lessened the degree of the TCA wound. Timing of application played a role in the case of occlusion with Vigilon.
Conclusion: Occlusives used in conjunction with TCA peels do not have a uniform effect on depth of necrosis. Ointments and Vigilon can be used without reducing the efficacy of the TCA peel. Multiple subjects and rigid control of variables are necessary in studies of TCA-induced necrosis.