Human papillomavirus (HPV) genotype and morphologic features of cutaneous warts reliably predict treatment outcomes, according to the results of a retrospective analysis published in the British Journal of Dermatology.1
The investigators sought to evaluate whether patient and morphologic characteristics of warts are predictive of HPV type and whether those features together are predictive of treatment response.
Using the Cutaneous WARTS (CWARTS ) diagnostic tool, the researchers scored 9 dichotomized morphologic wart characteristics: (1) arrangement (confluent/multiple), (2) level (elevated or skin level), (3) aspect (rough/lobed or smooth/not lobed), (4) border (sharply or not sharply circumscribed), (5) color (lighter/skin color/yellow or red), (6) presence of white skin flecks, (7) presence of black dots (capillary thrombosis), (8) border erythema, and (9) callus.
A total of 311 warts from 159 patients were available for HPV testing. Overall, 62.3% of the participants (99 of 159) were women, which was most prominent in the plantar wart group. Patients in the common wart group were somewhat older. The duration of the warts was somewhat longer in the plantar wart group. The number and size of the warts were evenly distributed between common and plantar warts and between the treatment arms (monochloroacetic acid, cryotherapy, cryotherapy plus salicylic acid).
With respect to morphologic features, most common and plantar warts were solitary, elevated, rough, and sharply circumscribed, with white skin flakes, black dots, and callus. Plantar warts were significantly more likely than common warts to be characterized by a rough surface with white flakes, black dots, and callus (P <.05). An erythematous border was observed significantly more often in common warts vs plantar warts (P <.05). The presence of black dots was strongly predictive of any type of HPV in a wart.
Regarding HPV types, 34 warts in 11.3% of patients (18 of 159) had no detectable HPV DNA. Overall, 43 warts in 23.3% of patients (37 of 159) contained ≥2 types of HPV. Multiple HPV types could be present in a single wart or in different warts in the same patient.
When treated with monochloroacetic acid or a combination of cryotherapy and salicylic acid, HPV genotype was the strongest predictor of treatment response. Of note, there was a significantly decreased treatment response if the warts contained HPV genotypes HPV2, HPV27, and HPV57.
The investigators concluded that based on the study findings, HPV DNA testing should be considered for the development of new wart therapies in order to determine the most optimal treatment.
Hogendoorn GK, Bruggink SC, de Koning MNC, et al. Morphological characteristics and human papillomavirus genotype predict the treatment response in cutaneous warts. Br J Dermatol. 2018;178(1):253-260.