Treatment of chronic wounds with methylene blue photodynamic therapy: A case report

Methylene blue (MB) mediated photodynamic therapy (PDT) is an emerging treatment for different kinds of skin lesions and ulcers. Our case report aims to assess its potential in treating diabetic foot ulcers, venous leg ulcers, and pressure ulcers. Patients presented with complex chronic wounds larger than 40 cm(2) with low healing potential. Once a week, patients had an aqueous formulation of MB at a concentration of 10 mg/mL (1% w/v) applied topically on their wounds, which were then irradiated with a light-emitting diode (LED) light source (660 nm, 3.8 J/cm(2)) with 9 mW/cm(2) on tissue surface. Symptom improvement and recurrence rates were assessed with a long-term follow-up from 2018 to 2021. The results were satisfactory, with significant wound size reduction, and a decrease in aspects indicative of infection including odor, presence of exudates, and purulence. After methylene blue-mediated photodynamic therapy (MB-PDT), patients showed significantly reduced wound secretion, no signs of local reaction, and no adverse effects such as burning sensation, pain, itching, skin ery-thema, or general malaise.