A novel human papillomavirus-induced 'doughnut wart' lesion treated with 5-aminolevulinic acid photodynamic therapy: A case report.

The present study reports 'doughnut wart', a novel human papillomavirus (HPV)-associated viral wart characterized by central regression and peripheral ring-shaped proliferation after cryotherapy or other treatments, likely due to treatment-altered microenvironments promoting viral spread. A 21-year-old female with a post-cryotherapy plantar doughnut wart was treated with CO2 laser debridement followed by three weekly 5-aminolevulinic acid photodynamic therapy (ALA-PDT) sessions. Complete healing was achieved with no recurrence at 1 year. During the sixth follow-up visit in June 2025, samples were collected from the patient for HPV detection, which confirmed the absence of recurrence. ALA-PDT eliminates HPV-infected cells through reactive oxygen species, activates local immunity (including immunogenic cell death) and preserves skin barriers, offering a precise, recurrence-reducing approach superior to conventional therapies, which can disrupt barriers and promote viral spread.