Table 5.

Periungual and subungual verruca studies

Study	Design	Therapy	Dosage	Sample size	Patient demographics (age/sex)	Nail involvement	Outcomes
Priya et al. (2019) [49]	Clinical trial	Intralesional vitamin D3	0.2–0.5 mL/session	14 patients	Mean age 28.57 years (12–49); sex NR	NR	Injections were performed at 2-week intervals till either complete resolution or maximum of 4 total sessions. Mean number of injection sessions till complete clearance was 3.05±0.83. 13/14 patients (92.9%) had complete clinical cure, 1/14 (7.1%) had moderate response (50 to <100% reduction in number of warts), and 0% (0/14) had mild response (<50% reduction in number of warts). No recurrences reported at 6-month follow-up.
Jakhar et al. (2019) [48]	Therapeutic pearl	Intralesional vitamin D3	0.2 mL/session	1 patient	NR	Fingernails	Clinical resolution of filiform wart of the thumbnail at 1-month post-therapy following 2 injections of vitamin D3 (0.2 mL) over 2-week intervals.
Raghukumar et al. (2017) [50]	Case series	Intralesional vitamin D3	0.2–0.5 mL (600,000 IU; 15 mg/mL)/session	2 patients	NR	NR	Injections were performed at 3-week intervals until complete resolution or for a maximum of 4 total sessions. 1/2 patients had complete resolution (100% regression) and 1/2 had partial resolution (>50% regression).
Xu et al. (2022) [51]	Retrospective observational	Topical tretinoin	Superficial X-ray therapy (total dose 16 Gy over 28 days); combination regimen of superficial X-ray therapy with topical tretinoin (occluded 8 h/day for 20 days)	36 patients	Mean age 32.58 years (6–86); 11 female patients and 25 male patients	NR	In the superficial X-ray therapy arm, 75% (18/24) of periungual warts achieved complete response, while 25% (6/24) of warts had a partial response. In the combination regimen arm, 92.7% (38/41) of periungual warts achieved complete clinical cure, while 7.3% (3/41) of warts had a partial response (p < 0.046).