Adverse Effects and Complications

Side effects and complications are varied and greatly influenced by postoperative care, patient selection, and operator skill. In general, the side-effect profile after Er:YAG laser resurfacing is similar but less severe and more transient when compared with those experienced after CO₂ laser resurfacing [34, 35, 36] (Table 7.2). Postoperative erythema, lasting an average of 4.5 months, is an expected occurrence in all CO₂ laser-treated patients and is a normal consequence of the wound-healing process. Erythema after short-pulsed Er:YAG resurfacing is comparably transient of 2–4 weeks duration [5, 22]. Even after the dual-mode Er:YAG laser treatment, erythema persists beyond 4 weeks in only 6% of patients [34]. Time to re-epithelialization averages 8.5 days after multipass CO₂ laser resurfacing compared with 5.5 days after Er:YAG resurfacing [5].Hyperpigmentation is a relatively common side effect–typically seen within 3–6 weeks after the procedure.After CO₂ resurfacing, the reported incidence is 5% in the periorbital area and 17–83% in other facial sites, with an even greater incidence in patients with darker skin tones [16, 32]. Hyperpigmentation also occurs after Er:YAG laser resurfacing and is more persistent if a variable-pulsed Er:YAG is used. However, when compared with multipass CO₂ resurfacing, hyperpigmentation after dualmode Er:YAG resurfacing resolves 6 weeks earlier [32]. Single-pass CO₂ laser resurfacing and multipass Er:YAG resurfacing, however, are comparable in terms of posttreatment erythema, re-epithelialization time, and hyperpigmentation [35]. Hyperpigmentation typically fades spontaneously but dissipates more rapidly with application of any of a variety of glycolic, azelaic, or retinoic acid creams, light glycolic acid peels, and/or hydroquinone compounds. Other mild and transient side effects that have been reported during wound healing include milia formation, acne exacerbation, and irritant or contact dermatitis [5, 16, 34, 36]. Hypopigmentation, on the other hand, is long standing, delayed in its onset (>6 months postprocedure), and is difficult to treat. Fortunately, it is seen far less frequently than is hyperpigmentation. Excimer laser and topical photochemotherapy have each shown some success in repigmenting affected areas [37].

Table 7.2. Side effects and complications of ablative laser skin resurfacing   Side effects   Mild complications   Moderate complications   Severe complications   Transient erythema   Prolonged erythema   Pigmentary change   Hypertrophic scar   Localized edema   Milia   Infection, (bacterial, fungal, viral)   Ectropion   Pruritus   Acne               Contact dermatitis

A potentially more serious complication of laser skin resurfacing is infection–viral, bacterial, or fungal. Even with appropriate antiviral prophylaxis, herpes infection (usually reactivation of latent virus) occurs in 2–7% of patients postoperatively [15, 38, 39].While antiviral prophylaxis is commonly prescribed, the use of postoperative antibacterials remains controversial, with one study showing no significant effect of antibacterial prophylaxis on infection rate [40].What is widely agreed upon is that patients must be followed closely during the postoperative period and placed on appropriate antibiotics if bacterial infection is suspected. If infections are left undiagnosed or untreated, systemic infection or even scarring could result [41]. Scarring has also been attributed to the use of aggressive laser parameters and/or overlapping or stacking of laser pulses, which leads to excessive residual thermal necrosis of tissue [5, 12, 16]. Improvement of these laser-induced burn scars has been affected by 585-nm pulsed dye laser irradiation, presumably by its vascular specificity as well as through stimulation of cellular mediators critical to wound healing [42].