Correspondence

Pyomyositis Complicating Acute Bacterial Endocarditis in an Intravenous Drug User

N Engl J Med 2000; 342:1614-1615May 25, 2000

Article

To the Editor:

Pyomyositis is very uncommon in the United States, and only about 100 cases have been reported in North America during the past 20 years.1 We describe a 48-year-old, homeless intravenous drug user in whom acute staphylococcal endocarditis and pyomyositis developed concurrently.

The patient was found febrile and confused and was brought to our hospital in October 1998. On admission, a computed tomographic (CT) scan of the head showed only a small lacunar infarct, and no cardiac murmur was heard. A transthoracic echocardiogram obtained soon after admission was interpreted as normal. Blood cultures grew methicillin-sensitive Staphylococcus aureus, and the patient's mental status improved after treatment with intravenous nafcillin was begun.

On the ninth hospital day, the patient noticed pain, tenderness, and swelling of his right calf. He denied self-injection or recent injuries to his right leg. A CT scan of the right calf showed a lucent area in the deep muscle, a finding highly suggestive of an abscess (Figure 1Figure 1CT Scan of the Right Calf.). Irrigation and drainage of the cavity were performed, and the purulent fluid grew methicillin-sensitive S. aureus. On the 10th hospital day, a holosystolic murmur was detected. A transesophageal echocardiogram showed a vegetation, 1.5 by 2.0 cm, on the mitral valve (Figure 2Figure 2Transesophageal Echocardiogram.). Because of the newly discovered endocarditis, oral rifampin was added to the treatment regimen. The patient completed a six-week course of nafcillin and rifampin, and to date, there has been no recurrence of endocarditis or of pyomyositis.

We suspect that the patient had endocarditis before admission and that it was missed on auscultation and transthoracic echocardiography. Fowler et al. found that transesophageal echocardiography was much more sensitive than transthoracic echocardiography in detecting vegetations.2 We recommend transesophageal rather than transthoracic echocardiography as a tool during the initial workup for endocarditis. Tumeh et al. demonstrated the usefulness of CT scanning in evaluating pyomyositis.3 Therefore, pyomyositis should be considered and evaluated by prompt examination of the affected area with CT scanning or magnetic resonance imaging when a patient presents with muscular pain, tenderness, and swelling.

Tze Shien Lo, M.D.
Mary G. Mooers, M.D.
Larry J. Wright, M.D.
LDS Hospital, Salt Lake City, UT 84143

3 References

1. 1

   Christin L, Sarosi GA. Pyomyositis in North America: case reports and review. Clin Infect Dis 1992;15:668-677
   CrossRef | Web of Science | Medline

2. 2

   Fowler VG Jr, Li J, Corey GR, et al. Role of echocardiography in evaluation of patients with Staphylococcus aureus bacteremia: experience in 103 patients. J Am Coll Cardiol 1997;30:1072-1078
   CrossRef | Web of Science | Medline

3. 3

   Tumeh SS, Butler GJ, Maguire JH, Nagel JS. Pyogenic myositis: CT evaluation. J Comput Assist Tomogr 1988;12:1002-1005
   CrossRef | Web of Science | Medline

Citing Articles (5)

Citing Articles

1. 1

   Steven D. Burdette, Richard R. Watkins, Ken K. Wong, Stephanie D. Mathew, Donald J. Martin, Ronald J. Markert. (2012) Staphylococcus aureus pyomyositis compared with non-Staphylococcus aureus pyomyositis. Journal of Infection
   CrossRef

2. 2

   Aristotelis Tsiakalos, Sarah P Georgiadou, Ioannis Anastasiou, Nikolaos V Sipsas, Athanasios Tzioufas. (2011) Bilateral dilation of the urinary tract due to iliopsoas pyomyositis: a case report. Journal of Medical Case Reports 5:1, 195
   CrossRef

3. 3

   Lorne N. Small, John J. Ross. (2005) Tropical and Temperate Pyomyositis. Infectious Disease Clinics of North America 19:4, 981-989
   CrossRef

4. 4

   John R Ebright, Barbara Pieper. (2002) Skin and soft tissue infections in injection drug users. Infectious Disease Clinics of North America 16:3, 697-712
   CrossRef

5. 5

   J. G. Heckmann, C. J. G. Lang, M. Haselbeck, B. Tomandl, B. Neundorfer. (2001) Tropical pyomyositis. European Journal of Neurology 8:3, 283-284
   CrossRef