Photodynamic therapy: an innovative approach to the treatment of keloid disease evaluated using subjective and objective non-invasive tools

Sara Ud-Din, Grace Thomas, Julie Morris, Ardeshir Bayat

Optimal management for keloid disease (KD) is ill defined, with surgical excision resulting in recurrence rates over 50 %. Photodynamic therapy (PDT) uses light to activate a photosensitiser localised in diseased tissues. Two recent case studies and in vitro studies on keloid-derived fibroblasts indicate potential use of PDT in treating KD. Therefore, we hypothesized that there may be a role for PDT in the treatment of KD. Twenty KD patients were divided into three groups; existing keloid scar, post-surgical debulking and post-total surgical excision. Patients underwent three treatments of PDT at weekly intervals. Methyl aminolevulinate photosensitiser applied 3 h prior to PDT, administered at 37 J/cm(2). Non-invasive measures provided quantitative data for pliability, haemoglobin, melanin, collagen and flux. Pain and pruritus scores were measured and patients' were monitored for KD recurrence. All patients had reduced pain and pruritus scores. Haemoglobin flux (p = 0.032), collagen (p = 0.066) and haemoglobin levels (p = 0.060) decreased from week 1 to 3 in all except one patient where measurements were taken and pliability increased significantly (p = 0.001). Increases in pliability were significantly related to decreases in flux (p = 0.001). Only one patient with a keloid in a stress-prone anatomical location experienced recurrence of KD. All other patients had no recurrence at 9-month follow-up. Minimal side effects were reported. In conclusion, PDT reduces scar formation in KD evidenced by decreased blood flow, increased pliability, decreased collagen and haemoglobin levels. These findings indicate potential utility of PDT in the treatment of KD.