[1835–45; mast- + -itis]This word is first recorded in the period 1835–45. Other words that entered Englishat around the same time include: communism, daisy chain, hybridize, protein, serial-itis is a suffix used in pathological terms that denote inflammation of an organ (bronchitis; gastritis; neuritis) and hence, in extended senses, nouns denoting abnormal states or conditions, excesses,tendencies, obsessions, etc. (telephonitis; baseballitis)