A topical corticosteroid is a synthetic (man-made) corticosteroid medication that is used to address skin conditions like eczema. It's available in several applications, like creams, gels, foams, lotions, oils, shampoos, pads, and sprays. Side effects can include worsening skin infection, spreading of the infection, inflamed hair follicles (folliculitis), and thinning of the skin.