Pigmented guinea pig skin irradiated with Q-switched ruby laser pulses. Morphologic and histologic findings

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Arch. Dermatol.; (United States)

DOI:https://doi.org/10.1001/archderm.1989.01670130045004· OSTI ID:6535430

Dover, J S; Margolis, R J; Polla, L L; Watanabe, S; Hruza, G J; Parrish, J A; Anderson, R R

Q-switched ruby laser pulses cause selective damage to cutaneous pigmented cells. Repair of this selective damage has not been well described. Therefore, using epilated pigmented and albino guinea pig skin, we studied the acute injury and tissue repair caused by 40-ns, Q-switched ruby laser pulses. Gross observation and light and electron microscopy were performed. No specific changes were evident in the albino guinea pigs. In pigmented animals, with radiant exposures of 0.4 J/cm2 or greater, white spots confined to the 2.5-mm exposure sites developed immediately and faded over 20 minutes. Delayed depigmentation occurred at seven to ten days, followed by full repigmentation by four to eight weeks. Regrowing hairs in sites irradiated at and above 0.4 J/cm2 remained white for at least four months. Histologically, vacuolation of pigment-laden cells was seen immediately in the epidermis and the follicular epithelium at exposures of 0.3 J/cm2 and greater. Melanosomal disruption was seen immediately by electron microscopy at and above 0.3 J/cm2. Over the next seven days, epidermal necrosis was followed by regeneration of a depigmented epidermis. By four months, melanosomes and melanin pigmentation had returned; however, hair follicles remained depigmented and devoid of melanocytes. This study demonstrates that selective melanosomal disruption caused by Q-switched ruby laser pulses leads to transient cutaneous depigmentation and persistent follicular depigmentation. Potential exists for selective treatment of pigmented epidermal and dermal lesions with this modality.

• Research Organization: Massachusetts General Hospital, Boston (USA)
• OSTI ID: 6535430
• Journal Information: Arch. Dermatol.; (United States), Journal Name: Arch. Dermatol.; (United States) Vol. 125:1; ISSN ARDEA
• Country of Publication: United States
• Language: English

Related Subjects

560400* -- Other Environmental Pollutant Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL TISSUES
ANIMALS
BIOLOGICAL EFFECTS
BODY
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
EPIDERMIS
EPITHELIUM
GUINEA PIGS
HAIR
HYDROXY COMPOUNDS
LASER RADIATION
LASERS
MAMMALS
MELANIN
MICROSCOPY
NECROSIS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PATHOLOGICAL CHANGES
PIGMENTS
RADIATIONS
RODENTS
RUBY LASERS
SKIN
SOLID STATE LASERS
TISSUES
VERTEBRATES