Should the red area around the corn plaster be removed?

       Do not remove the reddish discoloration on the corn plaster. The plaster contains salicylic acid, which itself is red—hence the red appearance—and must not be wiped or peeled off. Corn plasters are typically salicylic acid–phenol plasters, and it is the salicylic acid that exerts the therapeutic effect against corns. Details are as follows:

       Salicylic acid is an organic acid currently believed to possess lipophilic properties, making it particularly effective on female skin. It softens the skin and acts on the stratum corneum: low concentrations (<3%) promote keratinocyte proliferation, whereas higher concentrations (>5%) produce keratolytic, desquamative, and caustic effects—thereby eliminating corns. Salicylic acid also removes hyperkeratotic follicles, helping unclog pores.

       Corns cause discomfort or pain during walking or wearing shoes due to localized friction. This condition does not resolve spontaneously and frequently recurs. When using corn plasters, the affected skin undergoes controlled chemical corrosion, followed by regeneration of new skin; however, recurrence remains common. Soaking the feet prior to application softens the skin and optimizes treatment efficacy; patients must ensure the plaster remains securely adhered.

       Patients should rest adequately, avoid excessive fatigue, and ensure sufficient sleep.