Answer:
The Obagi program is a modified trichloroacetic acid peel. The
skin is prepared for a minimum of 4 weeks with a regimen of 0.1% tretinoin,
4% hydroquinone, and 7% lactic acid application. The pretreatment
facilitates a more even penetration of TCA by inducing a compact keratin
layer and a uniformly thickened epithelial layer. The chemical peel
is performed with a solution of 41.7% TCA in diluent containing 10% glycerin
and a very small amount of the surfactant Saponin. The purpose of
the glycerin and saponin diluent is to slow the action of TCA in order
to produce clinical signs indicating the depth of injury. This allows
the operator to stop applying the TCA solution at the appropriate depth
of peeling. After a coating of the solution is applied, a 60-second
waiting period is observed for the clinical signs of TCA penetration. Any
additional coats of solution require intervening 60-second waiting periods
as well. A level 50:1 peel, into but not through the papillary dermis,
is indicated by a coarse wrinkling that appears when the skin is gently
pinched referred to as epidermal sliding. There is a light white frosting
with a strong pink background. At level 50:2 peel, upper reticular
dermis peel, the skin exhibits a uniformly solid white frosting with a
very faint pink or no pink background. At level 50:3 peel, deep dermis
peel, there is a total absence of background pink and a grayish hue appears.