The term Mycoplasma pneumoniae-induced rash and mucositis (MIRM) was recently proposed to identify the mucocutaneous condition secondary to M. pneumoniae infection that had historically been regarded among the more confusing pathologies of erythema multiforme and Stevens-Johnson syndrome. Based on a number of previous reports, these syndromes require differentiation since they have different prognoses and specific treatment requirements. We report a case of oral and genital erosions that strongly resembled MIRM without rash but were found to be secondary to a Chlamydia pneumoniae infection. After a thorough review of the literature on this subject, we propose that C. pneumoniae should also be considered a potential causative agent of MIRM and that this term should be amended to include C. pneumoniae infection.