Laser treatment of pigmented lesions and tattoos.

Benign pigmented lesions and tattoos are often very responsive to laser treatment. The chromophore in most cases is melanin, although other endogenous and exogenous pigments can be targeted. The chromophore and its distribution in the skin, as well as the underlying biological processes, all help determine the best laser, if any, for a given pigmented lesion. Epidermal lesions respond well to shorter wavelengths (up to 755 nm), whereas for deeper lesions, 694 nm or longer are typically used. The 1,064-nm Nd:YAG laser is best for treating darker skinned individuals. Multicolored tattoos may need several wavelengths to best target individual ink colors.

Pulsed dye laser therapy for sun damaged skin.

OBJECTIVE: The objective of this study was to evaluate the effectiveness of the pulsed dye laser (585 nm, 450 ms) in the treatment of sun induced wrinkles. DESIGN: Patients had one pulsed dye laser (585 nm) treatment. The treated areas were assessed by the following methods: grading of skin wrinkles at 6 weeks, 12 weeks, and 6-14 months after treatment by blinded observers and by light and electron microscopy. SETTING: An ambulatory care center at Abbott Northwestern Hospital (ANH) and the Laser & Skin Surgery Center of Northern California (LSSCNC). PATIENTS: Twenty patients were treated, half with mild to moderate and half with moderate to severe sun induced skin wrinkles. RESULTS: At last follow up 90% (9/10) of the mild to moderate wrinkles and 40% (4/10) of the treated patients with moderate to severe wrinkles had clinically observable improvement in their sun induced skin wrinkles. Histologic examinations of the treated areas showed a superficial dermal band of well organized elastin and collagen fibers replacing pre-treatment elastic tissue. Increased cellularity and mucin deposition was consistent with dermal collagen remodeling.

Laser treatment of tattoos.

All three Q-switched laser systems can effectively remove most tattoos with minimal scarring or other adverse sequelae. Despite advances in laser technology, all tattoos cannot be completely eliminated, and several wavelengths remain necessary to optimally treat multicolored tattoos. The major advantage of Q-switched laser irradiation to effect tattoo removal is the low risk of scarring associated with treatment. Limitations include the need for multiple treatment sessions, minimal to incomplete responses in some cases, and the possibility of pigmentary and textural changes. Research continues in an effort to perfect laser removal of tattoos.

Treatment of epidermal pigmented lesions with the frequency-doubled Q-switched Nd:YAG laser. A controlled, single-impact, dose-response, multicenter trial.

BACKGROUND AND DESIGN: The removal of benign, aesthetically important, pigmented lesions can be effectively treated with multiple modalities. Selective removal of the pigment by lasers is becoming increasingly popular. A three-center trial evaluated the effectiveness of the frequency-doubled Q-switched neodymium (Nd):YAG laser (532 nm, 2.0-mm spot size, 10 nanoseconds) in removing benign epidermal pigmented lesions with a single treatment. Forty-nine patients were treated for multiple lentigines (n = 37), for cafe au lait macules (n = 7), and for miscellaneous lesions (n = 5). Treatment areas were divided into four quadrants, irradiated with fluences of 2, 3, 4, or 5 J/cm2 and evaluated at 1- and 3-month intervals following treatment. RESULTS: For lentigines, response was related to dose with a greater than 75% pigment removal achieved in 60% of those lesions treated at higher energy fluences. Responses were more variable with other lesions, with fair-to-good improvement noted in most cases. Mild, transient erythema; hypopigmentation; and hyperpigmentation were noted in several patients, but resolved spontaneously within 3 months. No other textural changes, scarring, or other side effects were noted. CONCLUSION: The frequency-doubled Q-switched Nd: YAG laser (532 nm) safely and effectively treats benign epidermal pigmented lesions.

Cosmetic tattoo ink darkening. A complication of Q-switched and pulsed-laser treatment.

BACKGROUND: High-energy, short-pulse lasers, eg, Q-switched lasers, emitting visible and near-infrared light have recently been developed for removing tattoos, with little risk of scarring. The mechanisms of action, and possible adverse effects other than scarring and hypopigmentation, are not fully understood. OBSERVATIONS: We describe five cases of pulsed-laser-induced, immediate, irreversible darkening of cosmetic, white, flesh (skin-color), and pink-red colored tattoos. Irreversible ink darkening can be an insidious complication, because immediate whitening of the skin temporarily obscures the subsequently impressive color change. Among these cases, irreversible ink darkening occurred with Q-switched ruby (694 nm), Q-switched neodymium (Nd):YAG (1064 nm/532 nm), and pulsed green dye (510 nm) lasers. Attempts to remove the darkened ink with further laser treatment failed in two cases, and surgical excision was necessary. In the other three cases, subsequent laser treatments successfully removed the darkened ink. The red cosmetic tattoo ink used in one of the cases was placed in agar in vitro and was converted to a black compound immediately on Q-switched ruby laser exposure. Ferric oxide, a brown-red ingredient commonly used in cosmetic tattoos, was similarly tested and blackened in vitro by Q-switched ruby laser exposures. CONCLUSIONS: Although most tattoos are not darkened by laser treatment, short-pulsed lasers over a wide spectrum can cause immediate darkening of some tattoo inks. Patients should be warned of the potential for irreversible cosmetic tattoo darkening, and test-site exposures should be performed prior to treatment. In some cases, subsequent laser treatments may remove the blackened ink. The mechanism probably involves, at least for some tattoos, reduction of ferric oxide (Fe2O3, "rust") to ferrous oxide (FeO, jet black), but the chemical reaction that is involved remains unknown.

The Q-switched Nd:YAG laser effectively treats tattoos. A controlled, dose-response study.

BACKGROUND AND DESIGN: The Q-switched ruby laser was recently shown to remove tattoos without scarring. The Q-switched neodymium: yttrium aluminum garnet (Nd:YAG) laser, which targets black ink with a longer wavelength that has less absorption by melanin, should effectively treat tattoos with fewer pigmentary alterations. A prospective, blinded, controlled study was conducted to assess the ability of the Q-switched Nd:YAG laser (1064 nm, 10 ns, 5 Hz) to remove tattoos. Twenty-five patients with 39 blue-black or multicolored tattoos (14 previously untreated, 25 Q-switched ruby laser-resistant) were exposed in randomly derived quadrants with 6, 8, 10, or 12 J/cm2 at 3 to 4 week intervals for a total of four treatment sessions. RESULTS: An excellent response (> 75% ink removal) was seen in 77% of the black tattoos and more than 95% of the black ink cleared in 11 (28%) of 39 tattoos at 10 to 12 J/cm2 after four treatment sessions. Colored inks were not as effectively removed. Response was related to fluence with greatest improvement noted in the quadrants treated with 10 and 12 J/cm2. No significant side effects, including pigmentary changes or scarring, were noted. Histopathologic examination demonstrated persistence of tattoo ink in clinically clear areas and confirmed the absence of fibrosis and granulomatous changes. CONCLUSION: The Q-switched Nd:YAG laser (1064 nm) effectively treats black tattoos with an excellent cosmetic outcome. Bright colors were minimally responsive to treatment. Higher doses were more effective and equally well tolerated.

Focal dermal hypoplasia: four cases with widely varying presentations.

We describe four patients with focal dermal hypoplasia (FDH): a girl with classic FDH, a boy with cutaneous findings, an infant with severe multisystem disease, and the infant's mother, who had previously undiagnosed FDH. These patients illustrate the classic cutaneous manifestations of FDH and the variations that can exist within a family.

Clinical use of the Q-switched ruby and the Q-switched Nd:YAG (1064 nm and 532 nm) lasers for treatment of tattoos.

BACKGROUND: The desire to remove tattoos has probably been around as long as their existence. Recent technological advances in lasers have finally made it possible to remove tattoos without leaving an equally undesirable scar. OBJECTIVE: The purpose of this article is to review the use of the Q-switched ruby (694 nm) and the Q-switched Nd:YAG (532 and 1064 nm) lasers for effective removal of tattoo ink, with cosmetically appealing results. RESULTS: The Q-switched ruby laser (694 nm) effectively removes blue-black and green ink, may treat other colors less efficiently, and is frequently associated with transient pigmentary changes, including rare depigmentation. The Q-switched Nd:YAG laser at 1064 nm quickly removes black ink, as well as other colors less efficiently; pigmentary changes are much less frequent, correlating with its lower absorption by melanin. The 532-nm wavelength treats red ink effectively, but also leads to temporary hypopigmentation. Transient textural changes may be noted at all three wavelengths discussed, but scarring is rare. CONCLUSIONS: Q-switched lasers can remove tattoos without residual scarring. Efficacy of ink removal is dependent on the wavelength used for the targeted pigment.

Analysis of the carbon dioxide laser plume for simian immunodeficiency virus.

To determine the viability of the immunodeficiency virus in the laser plume after carbon dioxide (CO2) laser irradiation, multiple samples of culture medium containing concentrated simian immunodeficiency virus (SIVMAC at 1000 TCID50 cultured from HUT 78 cells) were irradiated with a continuous-wave CO2 laser at variable irradiances (from 400 W/cm2 for 5 seconds to 1600 W/cm2 for 300 seconds). The resultant plume was collected and cultured for the presence of SIV. A positive control consisted of handling an infected specimen identically to the test specimens, with the exception of CO2 laser irradiation. All test cultures remained negative over an 8 week incubation period, while the control was positive for viable SIV within 7 days. These results suggest that SIV is not viable in the laser plume after CO2 laser irradiation. Further investigation is necessary before extrapolating these results to the human immunodeficiency virus (HIV).

Eruptive seborrheic keratoses in a young woman with acromegaly.

The sign of Leser-Trélat, or eruptive seborrheic keratoses, is purported to be a cutaneous marker for many underlying malignancies. Elevation in levels of growth factors has been postulated to be the stimulus for the sudden eruption of multiple new seborrheic keratoses. In support of this hypothesis we present a case of eruptive seborrheic keratoses in a young woman with acromegaly and elevated levels of growth hormone.

Chronic infusion of agents that increase cyclic AMP concentration enhances the regeneration of mammalian peripheral nerves in vivo.

Our previous investigation indicates that forskolin, a robust activator of adenylate cyclase, promotes sensory nerve regeneration in amphibians. The present study was designed to determine if forskolin had a similar effect in mammals. We also wished to test the hypothesis that cyclic AMP modulates nerve regeneration by comparing the effects of chronically infused forskolin with the effects of infused dibutyryl cyclic AMP, 8-bromo cyclic AMP, and the phosphodiesterase inhibitor, theophylline. Our results indicated that all agents promoted some aspect of regeneration. The two which presumably generated the largest increase in cyclic AMP concentration, forskolin and 8-bromo cyclic AMP, had the most profound effect on axonal elongation. All agents decreased the time to sprout initiation, but theophylline produced the largest decrease and its effect was mimicked by caffeine, a methylxanthine with limited ability to inhibit phosphodiesterase. This suggests that sprout formation may be triggered by an increase in intraaxonal free Ca2+, possibly modulated by cyclic AMP. The role of cyclic AMP in axonal elongation remains to be determined, but may be associated with stimulation of protein synthesis in the nerve cell body.

Forskolin activation of adenylate cyclase in vivo stimulates nerve regeneration.

The previous demonstration of an increase and redistribution of adenylate cyclase activity in injured peripheral nerve suggests that an increase in neuronal cyclic AMP concentration could play a role in peripheral nerve regeneration. We report our finding that accumulating adenylate cyclase activity was translated into a twofold increase in cyclic AMP concentration in the regenerating nerve stump, coincident with the initiation and elongation of regenerative nerve sprouts. We sought to magnify the role of cyclic AMP in regeneration by using forskolin, a robust activator of adenylate cyclase, to produce an additional increase in neuronal cyclic AMP in situ. Forskolin in vitro produced an approximately 40-fold greater elevation in neuronal cyclic AMP than an equimolar (10(-5] concentration of isoprenaline. Moreover, the elevated cyclic AMP concentration persisted for at least 60 min in the continued presence of forskolin. Daily injection of forskolin into the dorsal lymph sac of Rana pipiens, or delivery of forskolin through an implanted osmotic pump produced a sustained 40% increase in the rate of sensory nerve regeneration in freeze-lesioned sciatic nerves. We conclude that an increase in cyclic AMP concentration and, presumably, the activation of appropriate protein kinases stimulates regenerative nerve growth following trauma.