Sulfur is used to treat many kinds of skin disorders. Sulfur cream, lotion, ointment, and bar soap are used to treat acne. Sulfur ointment is used to treat seborrheic dermatitis and scabies.
Sulfur is what's known as a keratolytic. When applied, a keratolytic dries the skin and makes for a thinner epidermis. As you know, a pimple occurs when your pore is blocked, trapping oil and bacteria within. Sulfur helps the skin shed quicker, thus unclogging the pore and healing the acne.
Sulphur can combats bacterial growth hence used in skin ointments.