Quantitative Assessment of Intralesional Bleomycin for Periungual Warts in Nicaragua: A Retrospective Case Series

Periungual warts, caused by human papillomavirus (HPV) infection, are notoriously difficult to treat due to high recurrence rates and resistance to conventional therapies, significantly impacting patient comfort and daily activities. Although intralesional bleomycin has shown promise for resistant warts, data from Central America are scarce. Furthermore, most existing efficacy assessments rely on subjective clinical scales or binary outcomes, with few studies employing serial, quantitative measurements of lesion area.

This study aimed to evaluate the therapeutic outcomes and safety profile of intralesional bleomycin in the management of periungual warts, using quantitative lesion area assessment (cm²) to objectively measure treatment response.

We conducted a retrospective case series of 15 patients diagnosed with periungual warts who received intralesional bleomycin therapy at the National Dermatology Center of Nicaragua between May 2020 and November 2022. Therapeutic response was assessed by percentage reduction in total lesion area (cm²) and number of lesions. Adverse events, treatment parameters, and duration were also recorded.

Regarding efficacy, 60% (9/15) of patients achieved complete remission (100% reduction in lesion area), 33.3% (5/15) showed an 80%-99% reduction, and 6.7% (1/15) experienced a 50%-79% reduction. Most patients (66.7%, 10/15) received two therapeutic sessions, with a total treatment duration of eight weeks in 66.7% (10/15) and four weeks in 33.3% (5/15). Adverse events were reported in 86.7% (13/15) of patients, most commonly pain (80%, 12/15), erythema (40%, 6/15), and post-inflammatory hyperpigmentation (33.3%, 5/15). Less frequent events included onychomadesis (20%, 3/15), edema (6.7%, 1/15), pruritus (6.7%, 1/15), and permanent partial nail plate loss (6.7%, 1/15). Among patients who achieved complete remission, no recurrences were observed during the six-month follow-up. The quantitative lesion area measurement confirmed a statistically significant reduction in lesion size across the cohort.

Intralesional bleomycin appears highly effective for periungual warts, achieving substantial reductions in quantitatively measured lesion area and high complete remission rates, with a mostly transient adverse effect profile. This study is among the first in Central America to report on bleomycin treatment for periungual warts and is, to our knowledge, the first to evaluate efficacy using serial quantitative measurements of lesion area (cm²).