A sudden outbreak is an unexpected and rapid increase in the occurrence of a disease or other phenomenon. In this crossword, the solutions for the term 'sudden outbreak' are RASH (4 letters), BURST (5 letters), and FLAREUP (7 letters). A RASH is a skin condition characterized by an itchy or painful eruption of the skin. A BURST is a sudden release of energy or emotion. A flareup is an increase in intensity or activity. All three terms can be used to describe a sudden outbreak.