Rapid spontaneous regression of long-standing cutaneous warts following human papillomavirus vaccination

To the Editor We report a case of spontaneous regression of chronic cutaneous warts in a 21-year-old female patient following human papillomavirus (HPV) vaccination, which provides insights into the potential therapeutic effects of HPV vaccination on cutaneous warts The patient had a wart-like lesion on her left hand that persisted for over a decade. The lesion first appeared in 2007 following a scald injury, which was left untreated. Over time, it developed between the proximal interdigital web of the left index and middle fingers, characterized by a smooth surface, firm texture, and absence of the typical cauliflower-like morphology (Fig. 1a). Initially asymptomatic, the patient disregarded the lesion until 2019, when she attempted self-treatment by puncturing it, resulting in localized bleeding. This likely led to the development of additional lesions on her left hand due to autoinoculation and viral spread. A prominent lesion later appeared on the palmar interdigital web between the index and middle fingers, showing the typical verrucous, cauliflower-like appearance with raised pigmentation and keratotic features (Fig. 1c). Despite lesion progression, the patient did not seek medical treatment. In March 2024, the patient received the complete three-dose series of the 9-valent HPV vaccine (Gardasil 9). Two months later, in May 2024, she experienced localized pain and swelling around the lesions, followed by spontaneous regression over several weeks. By September 2024, all lesions had resolved, leaving smooth, healthy skin with minimal residual discoloration (Fig. 1b, d), and no recurrence has been observed.Figure 1: Wart lesions. (a) Primary lesion - initial presentation. (b) Primary lesion - postvaccine resolution. (c) Trauma-induced appearance. (d) Postvaccine resolution.HPV is a viral family comprising over 200 types [1]. High-risk types, such as HPV 16 and 18, are strongly associated with the development of cervical, vulvar, and vaginal cancers, while low-risk types, such as HPV 6 and 11, are linked to benign lesions such as genital warts and laryngeal papillomas. Vaccination against HPV significantly reduces the incidence of these diseases. Conventional treatments for warts, including cryotherapy, laser therapy, topical medications, and surgical excision, are effective but often require prolonged therapy and carry a risk of recurrence, particularly in immunocompromised patients [2,3]. This case demonstrates that the preventive HPV vaccine not only protects against HPV infection but may also exert therapeutic effects on existing wart-like lesions. Despite not receiving conventional treatments, the patient’s lesions resolved spontaneously within months of vaccination. The immune response triggered by the vaccine likely facilitated the clearance of lesions caused by low-risk HPV types, highlighting the potential of HPV vaccines in immune modulation and lesion resolution. Recent interest in therapeutic HPV vaccines has been growing [4]. Studies have shown that injecting the HPV vaccine directly into lesion sites can effectively treat HPV-related lesions in many patients [5]. This approach offers a promising new direction for the treatment of HPV-related diseases, particularly chronic and refractory verrucous lesions. Given these findings, there is an urgent need to accelerate the development of therapeutic HPV vaccines to provide an effective treatment option for patients. Moreover, given the broad potential of the HPV vaccine, we advocate for widespread vaccination, including among men, to reduce the prevalence of related diseases and enhance public health outcomes. Acknowledgments The authors acknowledge all the clinical staff at our Department of Dermatology for their technical assistance and administrative support. Ethical statement: Informed consent was obtained from the participant included in the study. Authors’ Contributions: All authors have read and approved the final manuscript. Each author meets the authorship criteria and has contributed significantly to the research design, data collection, analysis, and drafting of the manuscript. The manuscript represents honest and original work. Conflicts of interest There are no conflicts of interest.