# Clinical efficacy and predictive factors of photodynamic therapy combined with recombinant mussel mucin repair dressing in treating post-inflammatory hyperpigmentation

## TL;DR

This study shows that combining photodynamic therapy with a mussel mucin dressing improves treatment of skin pigmentation issues in darker skin types.

## Contribution

The study introduces a novel combination therapy using recombinant mussel mucin with photodynamic therapy for post-inflammatory hyperpigmentation.

## Key findings

- Combined therapy achieved 42.3% pigment clearance at 4 weeks, significantly higher than controls.
- Melanin density reduction was 31.5% in the combined therapy group.
- Quality of life scores improved significantly with the new treatment.

## Abstract

To evaluate the efficacy and safety of photodynamic therapy (PDT) combined with recombinant mussel mucin repair dressing in treating post-inflammatory hyperpigmentation (PIH), and to assess its impact on patient quality of life.

In a prospective, controlled, non-randomized clinical study, we enrolled 310 patients (Fitzpatrick III–IV) with epidermal or dermal PIH. Patients underwent PDT by wavelength and energy protocol, followed by immediate application of recombinant mussel mucin repair dressing. Pigmentation area, melanin density, adverse events, recurrence, and quality of life were assessed over 14 months.

The combined therapy achieved significantly greater pigment clearance at 4 weeks (42.3 vs. 25.6% in controls, p < 0.001), larger melanin density reduction (31.5 vs. 17.2%, p = 0.002), fewer phototoxic reactions (6.5 vs. 14.1%, p = 0.021), and lower recurrence at 14 months (13.2 vs. 27.8%, p = 0.011). Patient-reported quality of life markedly improved (median DLQI score from 35 to 68, p < 0.001).

PDT combined with recombinant mussel mucin repair dressing provides superior pigment clearance, reduced recurrence, improved safety, and enhanced quality of life compared with standard therapy. This multimodal approach offers a promising option for PIH management in darker skin types.