Mycoplasma pneumoniae Pneumonia with Worsening Pleural Effusion Despite Treatment with Appropriate Antimicrobials: Case report

Mycoplasma pneumoniae are extremely small self-replicating free-living bacteria which can cause upper respiratory tract infections, including pharyngitis, sinusitis, ear pain, rhinorrhoea and pneumonia.^1,2M. pneumoniae pneumonia is described as atypical and accounts for 1–29% of community-acquired pneumonia cases.² The causative bacteria can be transmitted through aerosols as well as in settings which promote close physical contact, such as homes, schools, military barracks and dormitories.³ The post-exposure incubation period is between two to three weeks and infections are more prevalent among children and young adults.⁴ Common risk factors include age (i.e. younger children or older adults), immune status (i.e. immunocompromised individuals with HIV or those undergoing chemotherapy or taking steroids), smoking and pre-existing lung disease.⁵

Classic symptoms of M. pneumoniae infection include fever, cough and the production of sputum; in most cases, the disease is self-limiting and results in a good prognosis.⁶ However, M. pneumoniae pneumonia can be life-threatening, resulting in respiratory failure or acute respiratory distress syndrome in certain cases.⁷ However, pulmonary complications such as parapneumonic effusion are rare and occur mainly in children and adolescents; most cases are unilateral, low-volume and resolve with appropriate antimicrobial therapy.^8–10

M. pneumoniae pneumonia can be diagnosed by serology using an enzyme immunoassay. An acute infection is indicated by the detection of immunoglobulin (Ig) A and/or IgM, with a single titre of IgM greater than 1:64 or a four-fold rise in the IgG titre.^11,12 Polymerase chain reaction (PCR) analysis can also be used to detect M. pneumoniae in clinical samples of sputum and those of nasopharyngeal and throat swabs. However, microbial testing is not usually performed for outpatients with community-acquired pneumonia because empirical treatment is almost always successful.¹³ This case report describes a patient with pneumonia who was not initially tested for M. pneumoniae. The patient deteriorated and developed severe pleural effusion, despite the administration of appropriate antimicrobials, necessitating drainage.

Case Report

A 22-year-old woman presented to the Emergency Medicine Department of the Sultan Qaboos University Hospital (SQUH), Muscat, Oman, in 2017 with an eight-day history of fever associated with coughing, chills and rigors. Although her coughing was initially dry, she had begun producing yellow-green sputum on day five and developed shortness of breath on day seven....