Effect of MAL-photodynamic therapy on hypertrophic scarring

Patients with localised scleroderma receiving aminolevulinic acid (ALA)/methyl aminolevulinic acid (MAL)-photodynamic therapy (PDT) were noted to show a reduction in skin tightness, suggesting that this therapy reduces skin sclerosis. Karrer and colleagues treated patients with 5-ALA-PDT once or twice weekly for 3-6 months and in all patients the therapy was reported to be highly effective for sclerotic plaques. In view of the potential benefit of PDT in reducing skin sclerosis, the following study looks at the possible clinical and histological effects of topical PDT on the mechanism of scarring, looking particularly at hypertrophic scars.

Patients with long standing hypertrophic scars were treated with MAL-PDT on two occasions at week apart, and repeated for 3 sessions at 6-weekly intervals. PDT effect was studied by means of fluorescence imaging throughout the treatment and biopsies were taken prior to and 6 weeks post-treatment to observe histological changes.

Six weeks following the treatment the scarred areas had significantly softened and become more flexible clinically and histologically there had been a significant increase in elastin fibres. This suggests that ALA/MAL-PDT may be a useful treatment or adjuvant therapy in the treatment of scarring.