For many years, eucalyptus oil has been used to relieve coughing. Today, some over-the-counter cough medications have eucalyptus oil as one of their active ingredients. The Australian aborigines used eucalyptus leaves to treat wounds and prevent infection. Today the diluted oil may still be used on the skin to fight inflammation and promote healing. You can purchase creams or ointments that contain eucalyptus oil. These products may be used on minor burns or other injuries that can be treated at home. The anti-inflammatory properties of eucalyptus can ease symptoms of herpes. Applying eucalyptus oil to a cold sore may reduce pain and speed up the healing process.