What is the efficacy of salicylic acid in treating common wart (verruca vulgaris) infections?

From the Guidelines

Salicylic acid is an effective treatment for common warts, with a cure rate of 49% and a relative risk of 160 compared to placebo, as shown in a meta-analysis of five studies with 333 patients 1. The treatment works by promoting exfoliation of epidermal cells and stimulating host immunity, which may be an additional mechanism of action against warts. For optimal results, apply over-the-counter salicylic acid preparations (typically 17% for plantar warts or 12-17% for other locations) daily after soaking and gently filing the wart to remove dead skin. Before application, protect surrounding healthy skin with petroleum jelly, then apply the solution directly to the wart and allow it to dry completely. Treatment should continue until the wart completely disappears, which typically takes 3-6 months. Some key points to consider when using salicylic acid for common warts include:

• The method of application depends on the formulation, with wart paints recommended to be applied after abrading or paring down the lesion and/or soaking prior to application 1.
• Qualitative research has shown that patients find the treatment difficult due to irritation of the surrounding skin, and compliance with treatments is thought to be poor 1.
• A study looking at the effect of occlusion found a benefit when using a 17% SA gel with lactic acid 1.
• Recent trials have shown that salicylic acid is less effective than cryotherapy for the treatment of hand warts, but more effective than no treatment at all 1.
• The British Association of Dermatologists' guidelines for the management of cutaneous warts recommend salicylic acid as a first-line treatment for hand and foot warts, with a strength of recommendation A 1. Some other treatment options for common warts include:
• Cryotherapy, which has a cure rate of 49% for hand warts and 30% for plantar warts 1.
• Cantharidin, which has been shown to be effective in some studies, but has a lower cure rate than salicylic acid 1.
• Imiquimod, which has been shown to be effective in some studies, but has a lower cure rate than salicylic acid 1. It's worth noting that the efficacy of salicylic acid can vary depending on the location and type of wart, as well as the individual patient's response to treatment. In general, salicylic acid is a safe and effective treatment for common warts, with a low risk of serious side effects, and is recommended as a first-line treatment by the British Association of Dermatologists 1.

From the FDA Drug Label

For Dermatologic Use: Salicylic Acid 6% is a topical aid in the removal of excessive keratin in hyperkeratotic skin disorders including verrucae, and the various ichthyoses (vulgaris, sex-linked and lamellar), keratosis palmaris and plantaris keratosis pilaris, pityriasis rubra pilaris, and psoriasis (including body, scalp, palms and soles). For Podiatric Use: Salicylic Acid 6% is a topical aid in the removal of excessive keratin on dorsal and plantar hyperkeratotic lesions. Topical preparations of 6% salicylic acid have been reported to be useful adjunctive therapy for verrucae plantares.

The efficacy of salicylic acid in treating common wart (verruca vulgaris) infections is that it is a topical aid in the removal of excessive keratin in hyperkeratotic skin disorders, including verrucae. It is also reported to be a useful adjunctive therapy for verrucae plantares 2.

• The main use is to aid in the removal of excessive keratin.
• It can be used as an adjunctive therapy for verrucae plantares. Note that the label does not provide direct information on the overall efficacy of salicylic acid for common wart infections.

From the Research

Efficacy of Salicylic Acid in Treating Common Wart Infections

• Salicylic acid is considered a first-line therapy for treating common warts, particularly for single or few small warts of short duration 3.
• The treatment has been shown to be effective, with cure rates of 60% to 80% in 12 weeks 4.
• A study using high-potency (26%) salicylic acid found that 81% of patients experienced cure or significant improvement after only two weeks of treatment, with low incidence of irritation 4.
• Salicylic acid has the best evidence to support its effectiveness, but it is slow to work and requires frequent application for up to 12 weeks 5.
• Combination therapy of salicylic acid and cryotherapy may result in significantly higher remission rates 3.

Comparison with Other Treatments

• Cryotherapy with liquid nitrogen is a favorable option for many patients, with cure rates of 50 to 70 percent after three or four treatments 5.
• Other treatments, such as topical vitamin A, imiquimod 5% cream, and photodynamic therapy, have also shown promise in treating common warts 6, 7.
• However, salicylic acid remains a commonly used and effective treatment option for common wart infections 3, 5, 4.