Subjects in the two ALA-PDT treatment group had a 97.5 % mean reduction ( P < 0.00001 ) from the number of baseline actinic keratosis ; ALA-PDT plus ingenol mebutate gel group had an 86.7 % mean reduction ( P < 0.00001 ) ; while subjects in the ingenol mebutate gel alone group had a 91.7 % mean reduction from the number of baseline actinic keratoses .