Imiquimod as an antiaging agent.
BACKGROUND
Topical imiquimod therapy has proven to be effective for a variety of infectious, neoplastic, and inflammatory dermatologic diseases. Several published reports have validated the benefit of imiquimod therapy for actinic keratoses and superficial melanoma and nonmelanoma skin cancers. There is, however, limited evidence demonstrating the use of topical imiquimod application as an antiaging treatment.


OBJECTIVE
We examined the effectiveness of imiquimod 5% cream in the treatment of photoaging by evaluating pretreatment and posttreatment biopsy specimens and documenting the histologic changes.


METHODS
This study represents an extension of an earlier project in our department in which patients with biopsy-proven lesions of lentigo maligna (LM) were recruited from a university dermatology service, a hospital, and referrals from private practitioners for an open-labeled efficacy trial with daily topical application of 5% imiquimod for 3 months. Biopsy of clinically affected skin was carried out on all patients before and after treatment. Using a semiquantitative method, biopsy specimens were analyzed for changes in the dermal collagen table (solar elastosis vs papillary dermal fibroplasia). Additional parameters analyzed included epidermal changes (atrophy vs acanthosis, melanin content, and hypergranulosis) and inflammatory effects (epidermal and dermal cell populations along with presence of pigment incontinence). Variables were compared using paired Wilcoxan rank sums.


RESULTS
Of 26 evaluable patients who completed 3 months of daily application, 24 (>92.3%) showed a significant increase in papillary dermal fibroplasia (P < .0001) with associated reduction in solar elastosis (P = .0036). Other noteworthy findings were restoration of normal epidermal thickness (P = .0073) and melanization (P < .0001).


CONCLUSIONS
This study only evaluates the effect of imiquimod in the lesional skin of LM. It is not known whether the results are applicable to nonlesional, photoaged skin.


CONCLUSIONS
Topical imiquimod appears to induce reparative changes to the epidermis and the dermal collagen table in chronically sun-damaged skin associated with LM, indicating its potential use as an antiaging treatment. These findings need to be confirmed in photodamaged skin not associated with LM.
Metcalf
Sara
S
Department of Dermatology, University of Oklahoma, Oklahoma City, Oklahoma, USA.
Crowson
A Neil
AN
Naylor
Mark
M
Haque
Raashid
R
Cornelison
Raymond
R
D000634:Aminoquinolines / Q000008:administration & dosage* / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D002452:Cell Count; D003094:Collagen / Q000378:metabolism; D020405:Dermis / Q000378:metabolism / Q000473:pathology; D004334:Drug Administration Schedule; D004817:Epidermis / Q000378:metabolism / Q000473:pathology; D006801:Humans; D018327:Hutchinson's Melanotic Freckle / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology*; D000077271:Imiquimod; D008543:Melanins / Q000378:metabolism; D008544:Melanocytes / Q000473:pathology; D009824:Ointments; D015595:Skin Aging / Q000187:drug effects*; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology*
D000634:Aminoquinolines; D000970:Antineoplastic Agents; D008543:Melanins; D009824:Ointments; D003094:Collagen; D000077271:Imiquimod