Duration for Salicylic Acid Plaster Application in Corn Treatment
For corn treatment with 40% salicylic acid plasters, apply the plaster and leave it covered for 5 days before removal, as recommended by the British Association of Dermatologists. 1
Application Protocol
The standard approach involves:
- Prepare the corn by paring down or abrading the hyperkeratotic tissue before plaster application to enhance penetration 1
- Apply the 40% salicylic acid plaster directly to the corn lesion 1
- Cover the treated area with an antibiotic or occlusive dressing 2
- Leave in place for 5 days without removal 1
- Remove after 5 days and reassess the corn 1
This 5-day occlusion period allows adequate keratolytic action while minimizing the risk of excessive maceration or irritation of surrounding tissue.
Treatment Course and Follow-up
Multiple treatment sessions may be necessary:
- 79% of patients achieve complete resolution with one 5-day treatment session 2
- 12.5% require two sessions, and 6.9% need three sessions for complete corn removal 2
- Reassess at 3 months, when 34% of corns completely resolve with plaster treatment compared to only 21% with scalpel debridement alone 3
- Time to recurrence is significantly prolonged with plaster treatment compared to scalpel debridement alone 3
Critical Safety Precautions During the 5-Day Application
Avoid abrading surrounding normal skin during the initial paring, as this may spread infection or cause unnecessary irritation 1
Monitor for systemic toxicity signs, particularly when treating multiple corns:
- Limit treatment to less than 20% body surface area to prevent systemic salicylate absorption 1
- Watch for tinnitus, dizziness, headache, mental confusion, or hyperventilation, which indicate salicylate toxicity 1
- Exercise caution in patients with impaired hepatic or renal function, as systemic absorption can occur even with topical application 1
- Avoid combining with oral salicylate medications due to additive systemic effects 1
Special Populations Requiring Modified Approach
Avoid using 40% salicylic acid plasters on poor healing sites such as the lower leg, or use only under close podiatric supervision 1
The 5-day covered application period represents the optimal balance between therapeutic efficacy and safety, with research demonstrating superior outcomes compared to traditional scalpel debridement when used under appropriate supervision 3