Skin Care And The Topical Treatment Of Aging Skin

Clinical and histologic changes determine optimal treatment regimens for microdermabrasion

OBJECTIVE

To analyze the onset and extent of the dermatological changes associated with microdermabrasion.

METHODS

Eleven volunteers, aged 31-62 years old, underwent a series of six aluminum oxide microdermabrasion facial treatments spaced over 7 to 10-day intervals. White light photography and digital ultraviolet fluorescent photography and skin biopsies were obtained prior to the study, after three treatments, and after six treatments. A 90-day no-treatment period ensured, after which biopsies and photographs were taken.

RESULTS

Clinical improvements in dyschromia, actinic changes and fine rhytides were observed after six treatments. Compared with the controls, the treated areas demonstrated the following histological changes: epidermal thickening with basal cell hyperplasia and mitotic activity; flattening and widening of the rete pegs; papillary dermal thickening with deposition of collagen and elastic fibers; and perivascular inflammation in the dermis. After the no-treatment period some of the clinical and histologic changes persisted although they were less than those present immediately after the last treatment. Serial ultraviolet photography following microdermabrasion treatments revealed changes in the skin's pigmentation pattern that correlated clinically with improvements in dyschromia.

CONCLUSION

Clinical and histological changes are most likely secondary to a mechanism resembling a reparative process. The persistent changes after a period of no-treatment suggests that some of the changes could be permanent. Clinicians can use this data to better determine the optimal interval frequency and treatment intervals with microdermabrasion.

Novel mechanisms and devices to enable successful transdermal drug delivery

Optimisation of drug delivery through human skin is important in modern therapy. This review considers drug-vehicle interactions (drug or prodrug selection, chemical potential control, ion pairs, coacervates and eutectic systems) and the role of vesicles and particles (liposomes, transfersomes, ethosomes, niosomes). We can modify the stratum corneum by hydration and chemical enhancers, or bypass or remove this tissue via microneedles, ablation and follicular delivery. Electrically assisted methods (ultrasound, iontophoresis, electroporation, magnetophoresis, photomechanical waves) show considerable promise. Of particular interest is the synergy between chemical enhancers, ultrasound, iontophoresis and electroporation.