Subdeltoid bursitis: an unusual presentation of Streptococcus pneumoniae bacterial endocarditis.

To the Editor: A 68-year-old man presented to the ER with complaints of sudden onset, nonradiating right shoulder pain and fever for 10 days. There was no history of antecedent trauma or shoulder overuse. His past medical history was significant for medication-controlled chronic obstructive airway disease. On initial examination, temperature was 101[degrees]F, BP 110/65, pulse 100/minute, and respiratory rate 22/minute. Examination of the extremities revealed erythema, induration and tenderness over the anterolateral aspect of the right shoulder. Cardiac and systemic examinations were normal. Initial laboratory investigations showed a white cell count of 21,700 cells/cu mm with 90% polymorphonuclear cells. Magnetic resonance imaging (MRI) of the shoulder showed a very large subdeltoid bursal fluid collection consistent with bursitis associated with myositis (Fig.). Incision and drainage was performed and the patient was started empirically on intravenous vancomycin. Microscopic examination of the fluid revealed Gram-positive cocci in chains, and cultures were positive for Streptococcus pneumoniae (penicillin MIC--0.5 mcg/mL). Admission blood cultures were also positive for Streptococcus pneumoniae as the causative organism with the same profile. In view of persistent fever, a transesophageal echocardiogram was done, which revealed a mobile echo density on the anterior leaflet of the mitral valve suggestive of vegetation. He responded to four weeks of intravenous ceftriaxone and is symptom free at a 3-month follow up.

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Primary subdeltoid bursitis is uncommon due to its deep anatomic location compared to the superficial bursae where penetrating trauma predisposes to development of infection. Septic bursitis occurs in fewer than 2% of cases of endocarditis (1) presenting with an acute to subacute onset of pain and swelling in middle-aged males. About 50% of such patients have a skin lesion overlying the bursa, and nearly all patients have bursal tenderness. (2) Aspiration of bursal fluid is mandatory for the diagnosis. Ultrasound and MRI are advocated to rule out contiguous involvement of adjacent structures and document fluid collection. Occurrence of deep bursitis should always mandate a search for a primary focus.

Pneumococcal endocarditis usually presents acutely, and chronic valvular and immunologic abnormalities may not be clinically apparent. Hence, pneumococcal endocarditis can pose a diagnostic dilemma as was seen with our patient, who presented with septic bursitis. Siegel et al (3) observed that native valves are more commonly affected in Streptococcus pneumoniae endocarditis with tendency to destruction, distal embolization and eventual heart failure. Septic bursitis is an unusual presenting complaint in pneumococcal endocarditis. A high index of suspicion with a thorough physical examination and supportive investigations should be considered in patients with septic bursitis or pneumococcemia and persistent fever.

Siddharth Mukerji, MD

Roshan Patel, MD

Department of Medicine

College of Human Medicine

Daniel Havlichek, Jr, MD

Department of Medicine, Division of Infectious Diseases

Department of Microbiology and Immunology

College of Human Medicine

Michigan State University

East Lansing, MI

References

1. Cea-Pereiro JC, Garcia-Meijide J, Mera-Varela A, et al. A comparison between septic bursitis caused by Staphylococcus aureus and those caused by other organisms. Clin Rheumatol 2001;20:10-14.

2. Pien FD, Ching D, Kim E. Septic bursitis: experience in a community practice. Orthopedics 1991;14:981-984.

3. Siegel M, Timpone J. Penicillin-resistant Streptococcus pneumoniae endocarditis: a case report and review. Clin Infect Dis 2001;32:972-974.Letters to the Editor