Pediatric Mycoplasma pneumoniae Infection Presenting with Acute Cholestatic Hepatitis and Other Extrapulmonary Manifestations in the Absence of Pneumonia

Song, Won Jae; Kang, Ben; Lee, Hwa Pyung; Cho, Joongbum; Lee, Hae Jeong; Choe, Yon Ho

M. pneumoniae are primarily mucosal pathogens, which attach and enter the ciliated cells of the respiratory tract to produce proinflammatory cytokines causing acute cellular inflammatory reaction and resultant airway damage [4] . Hence, the consequence of M. pneumoniae infection is mainly pneumonia, known to account for up to 40% of cases of community-acquired pneumonia in children [4] . Although pneumonia is well known as the hallmark of M. pneumoniae infection, cases of extrapulmonary manifestations presenting in the absence of pneumonia have been rarely reported in both children and adults [2, 3, [5] [6] [7] . The pathomechanism of how extrapulmonary manifestations are capable of occurring in the absence of pneumonia remains unknown. However it seems that extrapulmonary manifestations due to M. pneumoniae infection occur according to one of the following mechanisms; 1) a direct type in which local inflammatory cytokines plays an important role induced by M. pneumoniae at the site of inflammation, 2) an indirect type in which autoimmunity or the formation of immune complexes plays an important role in the absence of M. pneumoniae at the site of inflammation, and 3) a vascular occlusion type in which obstruction of blood flow plays an important role, induced either directly or indirectly by M. pneumoniae infection [7, 8] .