Clinical Outcomes and Safety of Intralesional Vitamin D3 for Cutaneous Warts: A Retrospective Cohort Study From Sana'a, Yemen.

Background Cutaneous warts are common lesions caused by human papillomavirus (HPV). Conventional destructive therapies are often painful and associated with high recurrence rates. Intralesional vitamin D3 has emerged as an immunotherapeutic option, though clinical evidence remains inconsistent. This study evaluated the clinical outcomes and safety of intralesional vitamin D3 in a cohort of Yemeni patients. Methods This retrospective cohort study evaluated patients treated at two dermatology clinics in Sana'a, Yemen, between January and June 2025. Consecutive patients meeting the inclusion criteria were enrolled. Sixty-one patients with cutaneous warts received intralesional vitamin D3 (60,000-150,000 IU per session) biweekly for up to six sessions. The primary outcome was complete cure, defined as the total disappearance of all treated warts and restoration of normal skin texture. Secondary outcomes included partial response (≥50% reduction), adverse events, and recurrence rates. Data were analyzed using descriptive statistics and univariate logistic regression. Results The median patient age was 18 years (IQR 15-34), and 77.0% (n = 47) were female. Complete cure was observed in 36 patients (59.0%), while 20 (32.8%) showed partial improvement, yielding an overall response rate of 91.8% (95% CI 82.4-96.5). Procedural pain was the most common adverse event (75.4%), followed by transient localized erythema or swelling (13.1%). No serious adverse events or scarring occurred. No recurrence was documented during the six months of follow-up. In univariate analysis, younger age was associated with higher odds of complete response (OR 0.87 per one-year increase, 95% CI 0.81-0.93; p < 0.001). Conclusions Intralesional vitamin D3 was associated with a complete response in approximately 60% of patients and demonstrated a favorable short-term safety profile in this retrospective cohort. However, given the retrospective uncontrolled design, modest sample size, and limited follow-up, randomized controlled trials are required to establish definitive efficacy and control for spontaneous regression.