Case Presentation: A 32-year-old male with no significant past medical history presented to the emergency department with a 3-day history of anorexia, fever, and a rash after returning from a trip to Colorado. Additionally, he endorsed an 8-pound weight gain and dyspnea on exertion.Upon presentation, he was febrile, tachycardic and had a diffuse targetoid rash involving his palms and soles consistent with erythema multiforme. Initial labs showed hyponatremia, thrombocytopenia with no leukocytosis. A broad infectious workup was done given his travel history which was significant for a positive mycoplasma IgM confirmed with an immunofluorescence assay. His hospital course was complicated by the development of hypoxia. Chest x-ray showed bibasilar opacities, bilateral pleural effusions, and cardiomegaly; BNP was elevated to 1400. A subsequent transthoracic echocardiogram revealed severe global hypokinesis, biventricular enlargement, and eccentric hypertrophy with a left ventricular ejection fraction of 25%. He then underwent a cardiac MRI, which was consistent with myocarditis and showed an LV apical thrombus. He was started on guideline directed medical therapy for HFrEF, loop diuretics and 4 weeks of doxycycline. He clinically improved and was discharged to follow-up with a plan for a repeat echocardiogram after appropriate time on medical therapy.
Discussion: Mycoplasma pneumoniae (MP) is an atypical bacterium that is a common cause of upper respiratory tract infections, bronchitis and community acquired pneumonia, which can be causes for admission to hospitalist services. In addition to respiratory symptoms, there are extrapulmonary manifestations which include hematologic, neurologic, dermatologic, and, rarely, cardiac involvement. Cardiac involvement can include myocarditis, pericarditis, endocarditis, and intra-ventricular thrombi. The mechanism of extrapulmonary disease is multifactorial and may be related to bacterial direct invasion, inflammation, immune modulation, or vascular etiologies.This is an interesting case of mycoplasma associated myocarditis, complicated by heart failure with reduced ejection fraction, and LV thrombus. Myocarditis is a rare cardiac manifestation, occurring in approximately 1-5% of patients diagnosed with MP. Development of heart failure and an LV thrombus is an even rarer entity and has been infrequently reported in the literature. Given the significant morbidity that can occur as the result of extrapulmonary manifestations of MP, it is critical for hospitalists to recognize and treat suspected MP infections early.
Conclusions: This case highlights the importance for hospitalists to seek out early diagnostic testing for patients suspected to have MP and to recognize the broad range of extrapulmonary manifestations, especially cardiac involvement. Initiation of antibiotic therapy is paramount once MP is suspected as a diagnosis and treatment of subsequent extrapulmonary manifestations is critical to prevent further morbidity and possible mortality.