From the FDA Drug Label
The preferable method of use is to apply Salicylic Acid 6% thoroughly to the affected area and to cover the treated area at night after washing and before retiring. Ammonium Lactate Lotion is indicated for the treatment of dry, scaly skin (xerosis) and ichthyosis vulgaris and for temporary relief of itching associated with these conditions.
The best treatment for calluses is salicylic acid patches 1, as the label for salicylic acid mentions its application to affected areas, which can include calluses.
- Salicylic acid is used to treat various skin conditions, including those that cause thickened skin, such as calluses.
- Ammonium lactate is indicated for dry, scaly skin and ichthyosis vulgaris, but it is not specifically mentioned for calluses 2.
From the Research
Salicylic acid patches are the preferred treatment for calluses due to their ability to quickly and directly soften keratin in the skin and promote exfoliation of thickened areas. The most recent and highest quality study, 3, compared scalpel debridement versus salicylic acid patches in the treatment of plantar callosities and found that while scalpel debridement relieved pain more effectively, salicylic acid patches are still a viable and effective treatment option.
Key Points to Consider
- Salicylic acid works by softening the keratin in the skin and promoting exfoliation of the thickened areas, typically at concentrations of 15-40% in over-the-counter patches.
- Apply the patch directly to the callus, leave it on according to package directions (usually 24-48 hours), then gently remove dead skin with a pumice stone after soaking your feet in warm water.
- Repeat this process until the callus is gone, usually within 1-2 weeks.
- Ammonium lactate (usually 12% in lotions like AmLactin) is better for maintenance therapy or milder calluses, as it gently exfoliates and moisturizes simultaneously.
- People with diabetes or poor circulation should consult a healthcare provider before using either treatment, as they may need professional care to avoid complications.
Additional Considerations
- A study from 4 found that a treatment method using Canthacur-PS, which includes 30% salicylic acid, was effective in treating calluses with a high success rate and minimal side effects.
- Another study from 5 found that salicylic acid 6% in an ammonium lactate emollient foam vehicle was effective in treating mild-to-moderate scalp psoriasis, with significant reductions in psoriasis severity parameters.
- However, the study from 3 is the most relevant to the treatment of calluses and provides the strongest evidence for the use of salicylic acid patches.