A Pilot Split-Face Study Comparing Conventional Methyl Aminolevulinate-Photodynamic Therapy (PDT) With Microneedling-Assisted PDT on Actinically Damaged Skin

BACKGROUND: Topical photodynamic therapy (PDT) is an approved treatment for superficial nonmelanoma skin cancers. To enhance photosensitizer penetration into the epidermis, microneedling (MN) devices or ablative carbon dioxide lasers are combined with PDT. OBJECTIVES: To compare the efficacy and safety of MN-assisted PDT with that of conventional PDT in human skin field cancerization. MATERIALS AND METHODS: Ten patients with multiple actinic keratoses (AKs) and photodamage were randomized to receive conventional methyl aminolevulinate (MAL) with previous gentle curettage on one side of the face and MAL-PDT combined with 1.5-mm-length MN on the other side after MAL application. After a 90-minute incubation, patients were illuminated with a red light-emitting diode and evaluated for improvement of photodamage, clearance of AKs, and side effects before and after 30 and 90 days. RESULTS: At day 30, global scores for photodamage, mottled pigmentation, roughness, and sallowness improved on both sides (p < .05), but fine lines improved only on the MN-PDT side (p = .004). At day 90, facial erythema (p = .04) and coarse wrinkles (p = .002) also improved on the MN-PDT side, in addition to fine lines for conventional MAL-PDT (p = .01). Erythema (p = .009), edema (p = .01), crusting (p = .01), and pain (p = .004) were more common and intense on the MN-PDT side. One patient developed a secondary bacterial infection at day 7 on the MN-PDT side. Average AK clearance was 88.3%, with no difference between the sides. CONCLUSION: Microneedling-assisted PDT is a safe and effective method and can produce superior cosmetic results to conventional MAL-PDT for improving photodamaged skin. Further larger prospective studies are needed to determine whether the addition of MN decreases actinic keratosis.