Pseudomonas sternoclavicular pyarthrosis.

Abstract: Most cases of Pseudomonas pyarthrosis affecting the sternoclavicular joint have been reported in immunosuppressed intravenous drug users. We report a case of Pseudomonas pyarthrosis in a man who was otherwise immunocompetent, except for his age. A 66-year-old white man presented to the clinic with a 1-month history of right-sided shoulder and arm pain associated with swelling of the upper part of the chest in the region of the right sternoclavicular joint. The chest radiograph revealed opacity in the right superior mediastinum. Computed tomography scan of the chest confirmed a mass in the right sternoclavicular region with associated osteolysis of the clavicular head. A needle biopsy of the mass was negative for malignancy. An open biopsy specimen showed evidence of chronic inflammation without evidence of malignancy, and culture of the tissue grew Pseudomonas aeruginosa. The patient's symptoms improved after extensive incision and drainage of the affected area followed by treatment with antibiotics for 6 weeks.

Key Words: immunocompetent host, Pseudomonas aeruginosa, pyarthrosis, sternoclavicular joint

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Bone and joint infection in general caused by Pseudomonas organisms is a very well-described entity primarily affecting immunocompromised hosts. Sternoarticular joint involvement in particular has been reported mainly in young male intravenous (IV) drug abusers. A primary site of infection is usually not discernible, and the pathophysiology remains obscure. (1-5)

Case Report

A 66-year-old white male presented with a 1-month history of right-sided shoulder and upper arm pain; swelling had subsequently developed in the upper part of his chest in the region of the sternoclavicular joint. There was no history of trauma, surgery, or soft tissue infection. The patient had no history of any chronic medical diseases. He denied IV drug abuse. On examination there was a firm, tender erythematous soft tissue mass (5 X 3 cm in size) in the region of the right sternoclavicular joint. He had tenderness and limited range of motion in the right shoulder. He was afebrile and his white blood count was 9,500/m[m.sup.3] with a left shift. X-ray film of the chest (Fig. 1) revealed an opacity in the right superior mediastinum. Computed tomography scan of the chest (Fig. 2) confirmed a mass in the right sternoclavicular region with associated osteolysis of the clavicular head. CT guided biopsy of the mass was negative for malignancy. An open biopsy specimen of the mass showed evidence of chronic inflammation but no evidence of malignancy. Blood and urine cultures were negative. The patient underwent extensive incision and drainage of the affected area, followed by treatment with antibiotics for 6 weeks with significant improvement of symptoms.

Discussion

Pseudomonas infection of bones and joints results from hematogenous spread from another primary site or extension from contiguous foci. Blood-borne infections are most commonly seen in IV drug abusers and in conjunction with urinary tract or pelvic infections. Pseudomonas bone and joint infections occur in children, the elderly, the chronically debilitated, and those with underlying diseases. Pseudomonas infection of the sternoclavicular joints, sacroiliac joints, vertebrae, and symphysis pubi are seen in IV drug abusers. Joint involvement is usually monoarticular, with the sternoclavicular joint being affected more often than the sternochondral joint. The duration of symptoms before diagnosis is usually months, although more acute presentations sometimes occur. Most patients are persistently febrile, and physical findings include tenderness, swelling, and erythema across the affected joint. Leukocytosis is sometimes present and the erythrocyte sedimentation rate is almost always elevated. Arthrocentesis in these patients may yield fluid with typical characteristics of pyogenic infection, although smears of the fluid may not reveal bacteria. Exploratory arthrotomies are usually necessary. These infections have been treated effectively with an aminoglycoside administered for at least 6 weeks in combination with antipseudomonal penicillin. This appears to be the first case of Pseudomonas sternoclavicular pyarthrosis described in a patient who was not an IV drug abuser, and who was an immunocompetent host without any history of a chronic medical condition. The patient was also in an older age group than mentioned in the literature.

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Conclusion

Pseudomonas infection of the axial joints is seen in young male IV drug abusers with associated immunosuppression. In the case reported herein, the patient who developed sternoclavicular pyarthrosis caused by Pseudomonas aeruginosa was not an IV drug user, but was an immunocompetent host from an older age group, and without any chronic medical condition.

Accepted September 29, 2003.

Copyright [c] 2004 by The Southern Medical Association

0038-4348/04/9707-0705

References

1. Brancos MA, Peris P, Miro JM, et al. Septic arthritis in heroin addicts. Semin Arthritis Rheum 1991;21:81-87.

2. Bayer AS, Chow AW, Louie JS, et al. Sternoarticular pyarthrosis due to Gram-negative bacilli: report of eight cases. Arch Intern Med 1977;137:1036-1040.

3. Mandal AK, Fiala M, Oparah SS, et al. Osteolytic lesion indicating Pseudomonas sternal osteomyelitis. Arch Surg 1976;111:776-778.

4. Goldin RH, Chow AW, Edwards JE Jr, et al. Sternoarticular septic arthritis in heroin users. N Engl J Med 1973;289:616-618.

5. Meyers BR, Berson BL, Gilbert M, et al. Clinical patterns of osteomyelitis due to Gram-negative bacteria. Arch Intern Med 1973;131:228-233.

RELATED ARTICLE: Key Points

* Bone and joint infections caused by Pseudomonas organisms and resulting in pyarthrosis affecting the sternoclavicular joint are typically found among immunosuppressed intravenous drug abusers.

* This report describes a case of Pseudomonas pyarthrosis in a host who was not an intravenous drug abuser, and was fully immunocompetent.

Dinkar Kaw, MD, and Youngsook Yoon, MD

From the Department of Internal Medicine, Medical College of Ohio, Toledo, OH.

Reprint requests to Youngsook Yoon, MD. Department of Medicine, Medical College of Ohio, 3120 Glendale Avenue, Ruppert Health Center, Room 0012, Toledo, OH 43614-5809. Email: [e-mail]