Common Wart of Hand

Common warts (verruca vulgaris) of the hand are raised hyperkeratotic papules caused by human papillomavirus types 2, 4, 27 and 57. They occur on fingers, knuckles, nail folds and palms.

• Spread by direct contact and autoinoculation on sites of minor trauma (nail biting, shaving, skin picking).
• Highest incidence in school age children and young adults; increased risk in butchers, fish handlers and other occupational exposures.
• About 65 percent of childhood warts resolve in 2 years.

Well defined rough, skin coloured to grey brown papules with black dots, 2 to 10 mm.

• Periungual lesions disrupt the nail fold and may cause nail dystrophy; palmar lesions may be tender.
• Koebner phenomenon with lesions along scratch lines.
• Differential diagnosis: seborrhoeic keratosis, actinic keratosis, squamous cell carcinoma, keratoacanthoma, molluscum contagiosum, corn, lichen planus, acrochordon, amelanotic melanoma (periungual), subungual exostosis.
• Complications: pain, nail deformity, bleeding, secondary infection, spread to new sites, recurrence, scarring, malignant transformation in immunosuppression.

Clinical; dermoscopy shows thrombosed capillaries.

• Biopsy for atypical lesions, rapid growth, ulceration, or in immunosuppressed patients and periungual lesions that persist.
• HIV test for extensive or resistant warts.

Observation is reasonable; treat when painful, disfiguring, multiple, or in the immunosuppressed.

• Supportive: avoid biting and picking, keep skin moisturised, cover lesions, do not share towels or nail tools.
• Pharmacological: salicylic acid 17 to 26 percent paint or 40 percent plaster nightly after soaking and paring for up to 12 weeks. Fluorouracil 5 percent cream twice daily for 4 to 12 weeks for resistant or periungual lesions. Imiquimod 5 percent cream three times weekly for up to 16 weeks. Intralesional bleomycin 1 unit/mL, 0.1 to 0.5 mL per lesion. Intralesional Candida antigen or MMR vaccine 0.1 to 0.3 mL for multiple warts, repeated every 3 to 4 weeks.
• Procedures: cryotherapy with liquid nitrogen for 10 to 15 seconds every 2 to 3 weeks (up to 6 sessions); curettage with electrodessication; pulsed dye laser or CO2 laser for resistant lesions. Avoid deep destruction of the nail matrix.
• Special groups: pregnancy, avoid fluorouracil and bleomycin and use cryotherapy or salicylic acid; children, prefer salicylic acid and gentle cryotherapy; HIV and transplant recipients, treat early and consider combined therapy; periungual disease, expect slower response and more recurrence.
• Red flags: pigmented, bleeding or ulcerated lesion, destruction of nail, rapid growth, immunosuppression with extensive lesions, lesions not responding after 3 months.
• Follow-up: review every 2 to 4 weeks during treatment, then at 3 months; biopsy persistent atypical lesions.