Fractional photothermolysis for Photoaging of the hands

JIH M.H et al.

Dermatol. Surg. 2008; 34: 73-78

Sponsored by Reliant Technologies (replacement tips for laser and supplies and pathology fees for biopsies)

Introduction

Actinic damage is particularly common on the hands because few people use sun protection or sunscreen on their hands even if they do consistently protect their face.

Consists mainly of pigment alterations, skin textural changes (roughness, wrinkling).

Ablative lasers provide the best improvements in photoaging of the face but their use is limited on the hands due to significant downtime and the risk of scarring associated with poor healing of nonfacial skin:-Q-switched Nd:YAG and Alexandrite lasers improve skin pigmentation only.-Non ablative lasers improve texture but have no effect on dyschromia.

Fractional thermolysis uses a mid-infrared laser system that produces arrays of microscopic thermal wounds called microscopic treatment zones (MTZs) at specific depths and densities in the skin:-Areas surrounding these zones are spared from injury and this allows for rapid regeneration of thermally wounded skin. It is therefore potentially useable on all parts of the body without the risk of scarring.

The objective is to evaluate the efficacy and safety of fractional thermolysis for the treatment of photoaging of the hands.

Materials and Methods

Patient selection

-10 patients (9female) with phototypes II to IV were recruited from an outpatient clinic population.

-Mean age 60.6 years (43-71)

-Inclusion criteria: over 18, mild to moderate hand photodamage, willingness to follow post-treatment requirements, relatively equal photodamage on both hands.

-Exclusion criteria: isotretinoin usage in the past 6 months, allergy to topical lidocaine, keloid formation, pregnancy.

Study design-In accordance with Declaration of Helsinki (1975) guidelines-5 treatments at 2-3 weeks intervals using 1550nm diode pumped erbium fiber laser (FRAXEL SR, Reliant Technologies, Palo Alto, CA) on right or left hand.-At the end of study follow-up period, subjects offered complimentary laser treatment for untreated hand.

Laser treatment and follow-up

-wash with soap and water

-topical triple anesthetic applied one hour before treatment

-water-soluble blue dye applied to the treatment area to enable the intelligent optical tracking of the FRAXEL SR to detect areas to be treated.

-Treatment performed at a setting of 8-9mJ/MTZ with 10 passes at 250MTZ/cm2 (2500MTZ/cm2).

-Photographs performed before each Rx & at 1-3months after last Rx.

-Subjective Investigator and Patient assessment in skin roughness, wrinkling and pigmentation:-0 no improvement-less than 25% improvement-25-50% improvement-51-75% improvement-more than 75% improvement

-Skin Biopsies taken at baseline and at 1 and 3 months post last treatment

-Patients advised on sun avoidance and sunscreen use after laser Rx

-Statistical analysis with student’s test (P SMALLER THAN 0.05 ?)

Results

Figure 2 (clinical investigator): statistically significant results compared to baseline no statistical difference between month 1 and 3 except pigmentation (3.1 at month 1 and 2.6 at month 3).

Figure 3 (patient based): statistically significant results compared to baseline (EXCEPT WRINKLING), no statistical difference between month one and 3.

All patients were very satisfied and elected for treatment of the other hand.

Biopsies were obtained in 7 out of 10 patients:

-baseline: thinned epidermis, solar elastosis, loss frayed collagen

-month 1 and 3: thickening of the epidermis, notably increased collagen density with compact collagen fibers in the dermis (H and E, Trichrome de Masson).

Side effects: transient erythema and oedema post-treatment, lasting 2-4 days. No “unwanted” scarring, pigmentary alteration or any other adverse effect.

Discussion

Few studies for a variety of lasers exist for treatment of photoaging of the hands,

Extrinsic photoaging causes degenerative changes in the skin that are superimposed on the normal chronologic aging process. In fact, the hands often develop a greater degree of photoaging and, more often than not, more significant degree of photoaging compared to the face due to inadequate and inconsistent sunscreen use and the fact that makeup, which often acts as a physical block on the face, is generally not applied to the hands.

Non ablative laser treatments have less downtime, risk of infection, pigmentary alteration and scarring. All the more significant that hands have a functional role.

Duration of effectiveness could be several months. A recent study by Wanner and colleagues noted similar degrees of improvements in photodamage on the face, chest, and neck after fractional photothermolysis, and improvements were maintained up to 9 months post-treatment.

Within 24 hours, the epidermal basal layer is restored and microscopic epidermal necrotic debris (MEND) is noted as early as 1 day post-treatment. MENDs contain eliminated melanin pigment which are then shed for the skin within 7 days: this corresponds to the clinical improvement of dyschromia.

although no difference between month 1 and 3 was observed in the patient assessment for pigmentation, an improvement greater at month 1 than 3 was noted by the physicians. This could be explained by unsatisfactory following of sunscreen post treatment guidelines and thus unprotected UV exposure.

The clinical improvements were reflected in the histologic changes on the treated skin. Markedly increased collagen density was seen in the papillary and upper reticular dermis. Previous immunohistochemical studies have shown increased collagen III production around the treated MTZs by 7 days after RX and replacement of damaged collagen in the MTZs by three months post-RX.

Safe and effective, but more patients, longer follow-up periods, and different settings would be needed for evaluation of FRAXEL Rx of the hands

“Les mains ne mentent jamais”