Mycoplasma pneumoniae pneumonia is a community-acquired infection occurring primarily in children and young adults. Though it has been estimated that only 3 to 10 percent of patients 1 Clyde Jr, WA Mycoplasma pneumoniae respiratory disease symposium: summation and significance. Yale J Biol Med. 1983; 56: 523-527 PubMed Google Scholar , 2 Cassell GH Cole BC Mycoplasmas as agents of human disease. N Engl J Med. 1981; 304: 80-89 Crossref PubMed Scopus (258) Google Scholar with M pneumoniae respiratory illness develop pneumonia, up to 30 percent of all pneumonias in a general population may be caused by M pneumoniae1 Clyde Jr, WA Mycoplasma pneumoniae respiratory disease symposium: summation and significance. Yale J Biol Med. 1983; 56: 523-527 PubMed Google Scholar , 3 Murray HW Masur H Senterfit LB Roberts RB The protean manifestations of Mycoplasma pneumoniae infection in adults. Am J Med. 1975; 58: 229-242 Abstract Full Text PDF PubMed Scopus (207) Google Scholar , 4 Berntsson E Blomberg J Lagergård T Trollfors B Etiology of community-acquired pneumonia in patients requiring hospitalization. Eur J Clin Microbiol. 1985; 4: 268-272 Crossref PubMed Scopus (71) Google Scholar , 5 Foy HM Loop J Clarke ER Mansy AW Spence WF Feigl P et al. Radiographic study of Mycoplasma pneumoniae pneumonia. Am Rev Respir Dis. 1973; 108: 469-474 PubMed Google Scholar , 6 Fick Jr, RB Reynolds HY Changing spectrum of pneumonia-news media creation or clinical reality?. Am J Med. 1983; 74: 1-8 Abstract Full Text PDF PubMed Scopus (36) Google Scholar , 7 Izumikawa K Hara K Clinical features of mycoplasmal pneumonia in adults. Yale J Biol Med. 1983; 56: 505-510 PubMed Google Scholar , 8 Linz DH Tolle SW Elliot DL Mycoplasma pneumoniae pneumonia: experience at a referral center. West J Med. 1984; 140: 895-900 PubMed Google Scholar , 9 Garibaldi RA Epidemiology of community-acquired respiratory tract infections in adults: incidence, etiology, and impact. Am J Med. 1985; 78: 32-37 Abstract Full Text PDF PubMed Scopus (376) Google Scholar , 10 Koletsky RJ Weinstein AJ Fulminant Mycoplasma pneumoniae infection: report of a fatal case, and a review of the literature. Am Rev Respir Dis. 1980; 122: 491-496 PubMed Google Scholar , 11 White RJ Blainey AD Harrison KJ Clarke SKR Causes of pneumonia presenting to a district general hospital. Thorax. 1981; 36: 566-570 Crossref PubMed Scopus (125) Google Scholar In closed populations, up to one-half of all cases of pneumonia may be linked to M pneumoniae, 3 Murray HW Masur H Senterfit LB Roberts RB The protean manifestations of Mycoplasma pneumoniae infection in adults. Am J Med. 1975; 58: 229-242 Abstract Full Text PDF PubMed Scopus (207) Google Scholar Among family members, the infection rate may be as high as 81 percent in children. 12 Hanukoglu A Hebroni S Fried D Pulmonary involvement in Mycoplasma pneumoniae infection in families. Infection. 1986; 14: 1-6 Crossref PubMed Scopus (5) Google Scholar The illness usually follows a benign, self-limited course; however, it may be complicated by Swyer-James syndrome, massive pleural effusion, pulmonary fibrosis, bronchiolitis obliterans, and the adult respiratory distress syndrome, some proving fatal. Other organs including those involving neurologic, dermatologic, gastrointestinal, hematologic, cardiovascular, musculoskeletal, and renal systems may be involved.