Treatment Options for Recalcitrant Periungual and Subungual Warts

The talk reviews treatment options for recalcitrant periungual and subungual warts, emphasizing that nail unit warts can severely affect quality of life and are often painful, persistent, recurrent, and difficult to treat because of limited access and risk of nail matrix damage. Because nail unit warts can closely resemble squamous cell carcinoma in situ or Bowen disease, the speaker stresses recognizing clues such as red or black dots, white halo, and loss of dermatoglyphics, while maintaining a low threshold for biopsy in monodactylous, older, immunocompromised, longstanding, or treatment-resistant lesions. Among therapies, bleomycin is presented as the leading option, with about 50% to 100% efficacy using monthly treatments and either intralesional or multipuncture techniques, though pain and local effects are considerations. Other useful options include 5-fluorouracil with or without salicylic acid, imiquimod after salicylic acid pretreatment, and vitamin D3 injections, each with varying efficacy, cost, and side effects. Cidofovir also appears effective but is limited by high cost, and laser-assisted delivery is promising but still experimental. Cryotherapy is discouraged because of the small nail unit and risk of permanent dystrophy. The speaker also highlights emerging approaches such as iontophoresis-based antiviral therapy and cold atmospheric plasma, which may be effective and well tolerated, with plasma especially promising for future study.