Integumentary System
Lesson 5: Dermatological Drugs
5-12
5-12. REDUCTION OF CALLUS AND SCALES
a. The appearance of scales and calluses on the skin are usually the result of epidermal cells undergoing rapid multiplication. Calluses are most common on the soles of the feet over the metatarsal bones. Both scales and calluses can be treated by keratolytics (a substance which causes the epidermis to scale).
b. A keratolytic is an agent that causes sloughing off of the cornified epithelium (the horny or hard layer of the skin). A keratoplastic (mild keratolytic) effect is seen when the drug simply softens the keratin and loosens the cornified epithelium. Keratolytic agents are used to remove warts and corns and to treat severe acne. These agents are also used in the treatment of eczema, psoriasis, and seborrheic dermatitis.
c. Specific keratolytics include the following agents:
(1) Coal tar. This agent is used as a keratoplastic in the treatment of eczema, psoriasis, and seborrheic dermatitis.
(2) Resorcinol. Resorcinol is used as a keratoplastic in the treatment of acne and seborrheic dermatitis.
(3) Salicylic acid. This agent is used as a keratolytic when present in concentrations of five percent to twenty percent and as a keratoplastic when present in concentrations of one percent to two percent.
(4) Sulfur. Sulfur is used as a keratoplastic in the treatment of acne and seborrheic dermatitis.
(5) Tretinoin (Retin-AR). This agent is used in the treatment of severe acne. The application of the medication to the affected area will produce a horny layer of skin which is easily removed. It is important that the patient use this preparation as directed by the physician and package directions. Do not apply this medicine to windburned or sunburned skin, open wounds, inside the nose, around the eyes, or around the mouth. The patient should avoid exposing the area being treated to too much wind or sun (or sun lamp). When the patient begins using this product, he may find that he is more sensitive to cold temperatures and to wind; therefore, protection should be worn until he knows how he reacts. This product is available as a cream, liquid, or gel.
