Antimicrobial photodynamic therapy for the treatment of angular cheilitis in critically Ill patients: a prospective study

This preliminary prospective study aimed to evaluate the effectiveness of antimicrobial photodynamic therapy (aPDT) as an adjunct treatment for angular cheilitis (AC) in critically ill patients and to investigate its feasibility in a high-complexity hospital setting. The study included 13 patients admitted to the intensive care unit (ICU) of a referral infectious disease hospital in Northeastern Brazil. The aPDT protocol consisted of 0.1% methylene blue (10-minute pre-irradiation) followed by low-level laser therapy (660 nm, 4 J/point, 40 s) applied to three points per affected commissure. Clinical evolution was monitored at T1 (72 h), T2 (7 days), and T3 (follow-up), with lesions classified according to severity. Most patients presented severe systemic compromise, predominantly related to HIV infection and diabetes mellitus. In addition, 76.9% of patients exhibited concomitant oral candidiasis, and 92.3% were receiving systemic antifungal therapy. Complete lesion regression was observed in 40% of patients within 72 h (T1). By the final follow-up (T3), the overall clinical cure rate reached 61.5% (8/13), including cases of delayed resolution confirmed up to day 15. Although a 30.8% loss to follow-up occurred due to the inherent challenges of the intensive care setting, no adverse effects or complications were reported. Within the limitations of this preliminary study, aPDT demonstrated promising clinical applicability as an adjunctive approach for managing angular cheilitis in critically ill patients.