Am Fam Physician. 2021 Mar 15;103(6):337-343.
Topical corticosteroids are an essential tool for treating inflammatory skin conditions such as psoriasis and atopic dermatitis. Topical corticosteroids are classified by strength and the risk of adverse effects such as atrophy, striae, rosacea, telangiectasias, purpura, and other cutaneous and systemic reactions. The risk of adverse effects increases with prolonged use, a large area of application, higher potency, occlusion, and application to areas of thinner skin such as the face and genitals. When prescribing topical corticosteroids for use in children, lower potencies and shorter durations should be used. Topical corticosteroids can work safely and effectively in patients who are pregnant or lactating. They are available in formulations such as ointments, creams, lotions, gels, foams, oils, solutions, and shampoos. The quantity of corticosteroid prescribed depends on the duration of treatment, the frequency of application, the skin location, and the total surface area treated. Correct patient application is critical to successful use. Patients may be taught application using the fingertip unit method. One fingertip unit is the amount of medication dispensed from the tip of the index finger to the crease of the distal interphalangeal joint and covers approximately 2% body surface area on an adult. Topical corticosteroids are applied once or twice per day for up to three weeks for super-high-potency corticosteroids or up to 12 weeks for high- or medium-potency corticosteroids. There is no specified time limit for low-potency topical corticosteroid use.