Mycoplasma pneumoniae is a leading cause of respiratory infections, including “walking pneumonia.” There has been an outbreak in Tokyo and a large number of patients have been observed this season. This outbreak can continue and can also be recurrent. Common symptoms are, cough, throat pain, nasal discharge, ear pain and breathing difficulty. Diagnostic testing (rapid immunochromatographic antigen test) is not routinely performed so many patients can go unrecognized for long periods of time. Commonly used antibiotics may not be effective. Mycoplasma pneumoniae infections can be difficult to diagnose and treat, so be sure to discuss treatment strategies with your physician.