The invention describes compositions and methods of use for 2,5-dihydroxybenzene sulfonic acid compounds and pharmaceutically acceptable salts thereof. The invention provides methods for (a) treating skin cancer; (b) treating cancer of the organs; (c) treating leukemia; (d) improving the efficacy of chemotherapy, radiation therapy and/or cancer immunotherapy; (e) treating rosacea; and (f) treating psoriasis by administration of a composition comprising at least one 2,5-dihydroxybenzene sulfonic acid compound or a pharmaceutically acceptable salt thereof, and, optionally at least one therapeutic agent. Also disclosed are compositions comprising administration of at least one 2,5-dihydroxybenzene sulfonic acid compound, or a pharmaceutically acceptable salt thereof, and, at least one therapeutic agent. In the invention the 2,5-dihydroxybenzene sulfonic acid compounds or pharmaceutically acceptable salts thereof are 2,5-dihydroxybenzene sulfonic acid, calcium 2,5-dihydroxybenzenesulfonate, potassium 2,5-dihydroxybenzenesulfonate, magnesium 2,5-dihydroxybenzenesulfonate and diethylamine 2,5-dihydroxybenzenesulfonate.