Mysophobia, also known as verminophobia, germophobia, germaphobia, bacillophobia and bacteriophobia, is a pathological fear of contamination and germs. It is classified as a type of specific phobia, meaning it is evaluated and diagnosed based on the experience of high levels of fear and anxiety beyond what is reasonable when exposed to or in anticipation of exposure to stimuli related to the particular concept. William A. Hammond coined the term in 1879 when describing a case of obsessive–compulsive disorder (OCD) exhibited in repeatedly washing one's hands.