Energy-Based Devices for Exogenous Ochronosis: A Systematic Review of Randomized Controlled Trials and Primary Studies

Introduction Exogenous ochronosis (EO) is an acquired cutaneous disorder characterized by progressive dermal hyperpigmentation resulting from prolonged topical hydroquinone exposure. The deeply deposited ochronotic pigment within dermal collagen renders conventional therapies ineffective. Energy-based devices (EBDs) have emerged as the primary interventional strategy. This systematic review synthesizes evidence on EBD efficacy, safety, and patient-reported outcomes for EO treatment. Methods This systematic review followed PRISMA 2020 guidelines. A comprehensive search was conducted from inception to June 2025. Studies evaluating any EBD for confirmed EO with quantifiable outcomes were included. Risk of bias was assessed using Newcastle-Ottawa Scale and Cochrane RoB-2 tools. Results Fifteen primary studies (147 patients) were included. Q-switched alexandrite (755 nm) laser achieved 85–100% pigment clearance after 4–6 sessions. Q-switched Nd:YAG (1064 nm) and picosecond lasers demonstrated excellent outcomes in Fitzpatrick skin types III–VI. Combination therapies showed synergistic benefit in refractory cases. Adverse events were predominantly mild and transient. Discussion EBDs exploit selective photothermolysis to fragment dermal ochronotic pigment. Q-switched alexandrite remains the most validated monotherapy, while picosecond technologies offer superior precision with lower post-inflammatory hyperpigmentation rates. Significant heterogeneity and absence of standardized outcomes limit evidence comparability. Conclusion Q-switched lasers, particularly alexandrite and Nd:YAG, represent the most effective interventions for EO. Picosecond lasers and combination therapies show promising results. Standardized multicenter RCTs are urgently needed to establish evidence-based guidelines.