Dermatology is a medical specialty that focuses on the diagnosis and treatment of conditions of the skin, hair, and nails. Dermatologists are medical doctors who have completed specialized training in the diagnosis and treatment of skin conditions, including diseases of the skin, hair, and nails, as well as cosmetic concerns. Some common conditions that dermatologists treat include acne, eczema, psoriasis, rosacea, skin cancer, and warts. Dermatologists may also provide cosmetic treatments, such as Botox injections and laser skin resurfacing, to help improve the appearance of the skin.