Treatment of Benign Pigmented Lesions Using a Long-Pulse Alexandrite Laser
November 2012 | Volume 11 | Issue 11 | Original Article | 1327 | Copyright © November 2012
To evaluate the efficacy of a novel long-pulse alexandrite laser with contact cooling in the treatment of benign pigmented lesions.
Five patients were enrolled in the study. All patients presented with epidermal pigmented lesions on the arms, hands, chest,
or legs. Patients were all female with a mean age of 59 years. At the initial evaluation, baseline pigment readings were determined with
a pigment meter. Test spots were performed with escalating doses of alexandrite laser (ClearScan ALX, Sciton, Palo Alto, CA) deployed
by a 7-mm spot equipped with a 30 mm x 30 mm scanner and a 10-ms pulse duration. Contact cooling was used, and temperature
was maintained at 18°C to 20°C. Patients returned 4 to 7 days after test spots for evaluation for the purpose of optimizing settings. The
highest settings that allowed for epidermal preservation and crusting of the hyperpigmented lesions were applied for the remainder
of the treatment zones. Determinations of improvement were made by evaluation of photographs with standard settings using polarized
and nonpolarized images. At each appointment, baseline pigment measurements were made to ensure there were no significant
changes between treatment sessions. Two treatment sessions were performed approximately 4 weeks apart, and the final evaluation
was 3 months after the final treatment.
Evaluation by a panel of blind observers determined a mean improvement of approximately 30%. Darker lesions responded
better than lighter lesions. So-called low-contrast lesions performed the poorest. Pain was approximately 2/10 with the use of 5% lidocaine
numbing cream applied approximately 45 minutes before each procedure. Pain was most severe where there was underlying hair.
A long-pulse alexandrite laser equipped with contact cooling can achieve significant pigmentation improvement.
J Drugs Dermatol.
Treatment of solar lentigines can be accomplished
through several modalities, including the use of cryogen,
hyfrecation, and light-based options. Based on
the theory of selective photothermolysis,1 quality-switched
(QS) lasers have been employed to treat pigmented lesions
with great success. The high energy output and short pulse durations
offer precise, spatially confined heating of epidermal
pigmented lesions while avoiding significant heat diffusion
from the target.2 However, for patients who have dyschromia
involving a large portion of the face or with chronic bronzing,
treatment of large areas becomes labor-intensive and timeconsuming.
Intense pulsed light devices have the benefit of
larger spot sizes with efficacy that approaches that of QS lasers
in the treatment of pigmented lesions.3,4 Therefore, they have
utility in treating larger areas. As an additional alternative, the
efficacy and safety of treatment of these lesions with a longpulse
alexandrite laser with fixed pulse duration has been reported.
2,5 The following study further demonstrates the safety
and efficacy of a new long-pulse alexandrite laser (ClearScan
ALX, 755 nm, Sciton, Palo Alto, CA) that employs contact cooling
in the treatment of superficial pigmented lesions.
A total of 5 patients were enrolled and treated in this prospective
study after approval from the Scripps Institutional Review Board. Each patient was advised of the risks and benefits regarding
the procedure, and consent was obtained before
treatment. The study conformed to the guidelines of the 1975
Declaration of Helsinki. Patients in this study had a mean age
of 59 years and were all female. All patients had Fitzpatrick skin
types II and III, with 4 patients having type II skin. All had clinically
diagnosed lentigines on the arms, hands, chest, or legs.
Exclusion criteria included Fitzpatrick skin types V and VI, immunocompromised
patients, history of connective tissue disease,
age younger than 18 years or older than 75 years, the inability
to read and comprehend English, known photosensitivity,
pregnancy, recent tan, history of poor wound healing, scarring
in the treatment area and history of keloid formation, active local
or systemic infection, or history of isotretinoin use within 6
months before the initiation of treatment.
Each patient enrolled in the study underwent an initial evaluation
and test spot treatment to determine the most efficacious
and safe fluence for each individual. Follow-up full treatments
of designated areas were performed at subsequent visits.
Sites were photographed using a digital camera (D70, Nikon,
Melville, NY), with and without a cross-polarizing filter (Canfield
Imaging Systems, Fairfield, NJ). Topical anesthetic of 5% lido-