TretinoinRetinoidsKeratolytic AgentsAcne VulgarisLentigoOintmentsAdministration, TopicalPropionibacterium acnesSkin AgingCosmeticsDermatologic AgentsChemexfoliationAcitretinHyperpigmentationNicotinic AcidsMelanosisEmollientsKeratosis, ActinicTrichloroacetic AcidSkin CareFacial InjuriesCarcinoma, Basal CellReceptors, Retinoic AcidSkinIsotretinoinAdministration, CutaneousSkin PigmentationVitamin ADrug CombinationsAntineoplastic AgentsRetinoid X ReceptorsRetinol-Binding ProteinsDouble-Blind MethodEtretinateTetrahydronaphthalenesRetinaldehydeAcne KeloidBenzoyl PeroxideSebumFenretinideBenzoatesRetinol-Binding Proteins, CellularTreatment OutcomePropionibacteriumSebaceous Glandsbeta-Carotene 15,15'-MonooxygenaseVitamin A DeficiencyGram-Positive Bacterial InfectionsRetinal DehydrogenaseAnticarcinogenic AgentsCell Divisionbeta CaroteneTumor Cells, Cultured