Doxycycline is used to treat infections caused by bacteria, including pneumonia and other respiratory tract infections; certain infections of the skin or eye; infections of the lymphatic, intestinal, genital, and urinary systems; and certain other infections that are spread by ticks, lice, mites, infected animals, or contaminated food and water. It is also used along with other medications to treat acne. Doxycycline is also used to treat or prevent anthrax (a serious infection that may be spread on purpose as part of a bioterror attack), in people who may have been exposed to anthrax in the air, and to treat plague and tuleramia (serious infections that may be spread on purpose as part of a bioterror attack). It is also used to prevent malaria. Doxycycline can also be used in people who cannot be treated with penicillin to treat certain types of food poisoning. Doxycycline (Oracea) is used only to treat pimples and bumps caused by rosacea (a skin disease that causes redness, flushing, and pimples on the face). Doxycycline is in a class of medications called tetracycline antibiotics.