Though not as much a safety issue, in some patients laser hair-removal treatment has a paradoxical effect of stimulating hair growth [129, 153-156]. It is considered a rare side effect of laser treatment. The most susceptible patients are the ones that have darker Fitzpat­rick skin type (III-V), are of Mediterranean descent, and receiving treatments on […]

23.4.3.1 Skin Cancer Unlike the well-established mechanism by which UV radiation can induce DNA muta­tions [137,138] leading to skin cancers [139], there is no scientific evidence that thermal energy from nonionizing IR-laser radiation can induce, promote, or progress cancer devel­opment [140]. It has been reported that IR exposure may provide some protective benefit against cytotoxicity […]

When skin is exposed to infrared light, there is the distinct possibility that some of the energy will result in secondary molecular/biochemical events. In experimental studies, various biological systems, that is, cell-based studies have reported changes in matrix met­alloproteinase (MMP) expression [131,132], perhaps as a result of free radical formation [133] and other events [134], […]

• Folliculitis: Inflammation of the hair follicles due to irritation or infection is an adverse effect largely associated with hair removal. Depending on the laser system and skin type treated, the incidence rate for folliculitis can range from <1% to as high as 35% [106]. • Blistering and Crusting: These dermal events are generally associated […]

Either hypo- (lightening) or hyper – (darkening) pigmentation have been reported to occur in subjects treated with lasers. Regrettably, the rigorous determination of pigmentary changes has not been documented. The pigmentary changes seen with laser treatment are generally transient, although the appearance/disappearance period can be from days to months. The clinical perception is that pigmentary […]

There are few studies in which pain from laser treatments have been evaluated exclu­sively. Because pain is subjective, the degree of such a sensation can be quite arbitrary. Nonetheless, like erythema, pain or discomfort is a common adverse event associated with nonablative laser treatments. In one study, pain produced by alexandrite and diode lasers was […]

The most frequent adverse effect in skin from nonablative laser treatment is erythema [ 108-111]. Erythema may be accompanied by edema, and is a reflection of the inflammatory response. Even when the clinician or operator uses careful precautions, erythema may be observed. In fact, the presence of perifollicular erythema or edema (inflammation sur­rounding the hair […]

In general, nonablative laser treatments are targeting melanin for hair removal and pigmen­tary lesions, oxyhemaglobin for vascular lesions, and extrinsic chromophores, that is, ink for tattoo removal. For the group of devices discussed, namely ruby, alexandrite, diode, Nd:YAG and IPL, thermal-related skin damage is fluence – or dose-dependent. Thus, as stated by Gold­berg [107] for […]

Up to this point, the types of lasers, their use in treatment of skin conditions, and the pre­sumed mechanism/mode of action have been described. The remainder of this chapter will review the toxicological or adverse events associated with the laser treatments of nonablative dermatological conditions. Considering the mechanism/mode of action of lasers with wave­lengths between […]