Treatment Approach for Multiple Warts on Hands and Forearms

Initial Treatment Strategy

The British Association of Dermatologists recommends salicylic acid as the first-line treatment for hand warts, with an "A" strength recommendation, due to its strong evidence-based efficacy and best safety profile 1
Salicylic acid promotes exfoliation and stimulates host immunity against the virus, and should be applied daily after paring down the warts, continuing for 3-4 months 1
Debride or pare down the wart before each application to remove the thick keratin layer that impedes penetration, and apply 15-26% salicylic acid preparations daily 1

If salicylic acid fails after 3 months, switch to cryotherapy with liquid nitrogen, which has a "B" strength recommendation from the British guidelines for hand warts 1
Freeze the wart for 15-30 seconds, and repeat treatments every 2-4 weeks, continuing for at least 3 months or six treatments before changing approach 1

For warts not responding to monotherapy, combine salicylic acid with cryotherapy, which has been shown to be more effective than salicylic acid alone 1
Contact immunotherapy with diphenylcyclopropenone (DPC) or squaric acid dibutylester (SADBE) can be used as a third-line option, with a strength C recommendation, applied from twice weekly to every 3 weeks for 3-6 months 1
Intralesional bleomycin can also be used as a third-line option, with a strength C recommendation, using a 0.1-1 U/mL solution injected or pricked into the wart after local anesthesia, with one to three treatments needed 1

Do not damage surrounding skin during paring or treatment, as this can spread the viral infection through autoinoculation, and change treatment modality if no substantial improvement after 3 provider-administered treatments or if warts haven't cleared after 6 treatments 3, 5
Avoid overtreatment, as scarring in the form of persistent hypopigmentation or hyperpigmentation is common with ablative modalities, and depressed or hypertrophic scars can occur if insufficient healing time between treatments 5