Scientific Background

Deep chemical peels create an injury through the papillary dermis into the upper reticular dermis and may extend into the midreticular dermis (0.6 mm). Deep peeling agents include phenol-containing preparation, or TCA in concentrations above 50%. Because of the risks associated with 50% TCA, such as scarring, TCA at these concentrations are not recommend for deep chemical peeling. Therefore, solutions containing phenol is the agent of choice for deep chemical peels [34]. In this section, the focus will be phenol-containing deep chemical peels.

Baker-Gordon phenol formula, occluded and unoccluded, is the most commonly used deep chemical peel. It is composed of a mixture of 3 ml 88% phenol USP, three drops of croton oil, eight drops of Septisol, and 2 ml of distilled water [43]. The mixture of ingredients is freshly prepared and must be stirred vigorously prior to application due to its poor miscibility. Phenol at 80% or higher concentrations precipitates epidermal proteins, thus forming a barrier hindering dermal penetration,while phenol diluted to 50% is keratolytic, allowing increased dermal penetration and hence greater dermal injury. Croton oil is an epidermolytic agent that augments phenol penetration. Septisol increases surface tension and is thought to slow the penetration of phenol [69]. The phenol peel can be applied under occlusion using waterproof zinc oxide nonporous tape or left unoccluded. Occlusion increases the penetration of the phenol by promoting tissue maceration and preventing the agent’s evaporation [70]. The unoccluded technique as modified by McCollough involves more cleansing of the skin and the application of more peel solution [71]. This may enhance the efficacy of the solution but without penetrating as deeply as in an occluded peel.


The reaction following application of phenol is characterized by keratocoagulative necrosis of the epidermis extending into the papillary dermis and by a marked inflammatory reaction. Epidermal regeneration begins within 48 h and is completed within 1 week. Dermal regeneration takes longer than epidermal healing and is characterized by rigid, compact collagen in the upper dermis replacing the disorganized collagen seen in elastosis [72].