Low-fluence carbon dioxide laser irradiation of lentigines

Journal Article · Mon Aug 01 00:00:00 EDT 1988 · Arch. Dermatol.; (United States)

DOI:https://doi.org/10.1001/archderm.124.8.1219· OSTI ID:6767499

Dover, J S; Smoller, B R; Stern, R S; Rosen, S; Arndt, K A

Low-fluence carbon dioxide (CO2) laser irradiation of skin has previously been shown to induce damage limited primarily to the epidermis. To evaluate whether this technique was therapeutically effective for pigmented epidermal lesions, ten lentigines caused by methoxsalen and ultraviolet light therapy were treated in one patient using the CO2 laser at fluences ranging from 3.0 to 7.7 J/cm2 for 0.1-s exposures with 4.5-mm spot size. Based on substantial clearing in seven of ten lesions treated, 146 solar lentigines were treated in five patients at fluences of 3.0, 3.7, or 4.4 J/cm2. Biopsies were performed on a total of 30 lesions immediately and 24 hours, seven days, and six weeks after irradiation. Of 125 lesions followed up clinically for six weeks, 12 cleared completely, 81 lightened substantially, and 28 remained unchanged. Only two demonstrated atrophic change. Hyperpigmentation or hypopigmentation did not occur. All lesions that improved had been treated at 3.7 or 4.4 J/cm2. Immediate histologic injury consisted of vacuolar and spindly change and subsequent vesiculation limited to the basilar epidermis. Twenty-four hours later there was epidermal necrosis with regeneration, 0.1 mm of dermal basophilia and stromal condensation, and a mild inflammatory infiltrate. These alterations were dose-dependent, with near complete epidermal necrosis and superficial dermal involvement at the highest fluence, and only focal epidermal necrosis at the lowest. At seven days, epidermal regeneration was complete with traces of melanin remaining in keratinocytes. Melanophages first appeared at seven days and persisted at six weeks, by which time the inflammatory infiltrate had cleared. No lentiginous proliferation was evident and epidermal pigmentation had become normal. Low-fluence CO2 laser irradiation is an effective means of damaging the epidermis with only minimal dermal change.

• Research Organization: Beth Israel Hospital, Boston, MA (USA)
• OSTI ID: 6767499
• Journal Information: Arch. Dermatol.; (United States), Vol. 124:8
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
EPIDERMIS
NECROSIS
LASER RADIATION
BIOLOGICAL EFFECTS
BIOLOGICAL REGENERATION
CARBON DIOXIDE LASERS
DOSE-RESPONSE RELATIONSHIPS
MELANIN
PATIENTS
SKIN
ANIMAL TISSUES
BIOLOGICAL RECOVERY
BODY
ELECTROMAGNETIC RADIATION
EPITHELIUM
GAS LASERS
HYDROXY COMPOUNDS
LASERS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PATHOLOGICAL CHANGES
PIGMENTS
RADIATIONS
RECOVERY
TISSUES
560400* - Other Environmental Pollutant Effects