Primary pyomyositis is a suppurative infection of striated muscle, the diagnosis of which is overlooked or delayed due to its rarity and vague clinical presentation. Though rare in the United States and temperate zones, pyomyositis is more frequently reported from tropical countries. The exact pathogenesis of pyomyositis is uncertain in most cases. The disease progresses through three stages with characteristic features and require a high index of suspicion to institute stage-wise treatment. Newer imaging methods, particularly magnetic resonance imaging, have facilitated the accurate diagnosis of the infection and of the extent of involvement. Early recognition with appropriate antibiotics in the pre-suppurative stage and prompt surgical intervention in the late stages form the corner stone of treatment. Delay in diagnosis can result in increased morbidity and mortality, especially in diabetics and immunocompromised state. Here, we report a case of primary paraspinal pyomyositis in a middle-aged female and emphasize the importance of early diagnosis and treatment.
Pyomyositis is an acute destructive and suppurative bacterial infection of striated muscle, with paraspinal muscle involvement occurring rarely. The first true description of pyomyositis was given by Scriba in 1885. The diagnosis is often delayed because of the unfamiliarity with the disease, lack of specific signs, atypical manifestations, and a wide range of differential diagnosis. It has predilection for the large muscle masses of the body, with no obvious local or adjacent source of infection. Though predominantly a disease of tropics, there have been reports of pyomyositis from non-tropical countries also. It affects previously healthy individuals and the disease is on the upswing in patients with immunosuppression, acquired immunodeficiency syndrome (AIDS) and diabetes. A high index of suspicion, early diagnosis and intervention are the key principles in the management of primary pyomyositis. A case of primary paraspinal pyomyositis (PPP) in a middle-aged female patient is discussed with emphasis on early diagnosis and treatment.
A 31-year-old female presented with fever and back pain of 15 days duration. Her past history was insignificant and she denied any history of trauma, tuberculosis and diabetes mellitus. On examination, the patient was ill looking, febrile with a pulse rate of 96/min. Right lumbar paraspinal region was edematous with local rise of temperature and tenderness [Figure 1]. Fluctuation was absent. Systemic examination failed to reveal a focus of infection elsewhere and there was no neurological deficit in the lower limbs. Laboratory analysis showed hemoglobin 11 g/dl, leukocytosis (20,000/mm3) and raised erythrocyte sedimentation rate (ESR; 100 mm/hour). Liver function tests were within normal limits. Blood urea nitrogen and serum creatinine were within normal limits. Enzyme-linked immunosorbent assay (ELISA) tests for human immunodeficiency virus (HIV) and HBsAg were non-reactive. The peripheral smear revealed reactive neutrophilia with toxic changes in the neutrophils. Urine analysis and culture were unremarkable. X-ray chest and thoraco-lumbar spine was normal. Computerized tomography (CT) showed bulky right posterior paraspinal muscle with heterogeneously hypodense lesion revealing mild peripheral partial rim enhancement with predominantly nonenhancing hypodense center suggestive of abscess formation. The abscess was seen to displace the right kidney anteriorly with maintained fat planes [Figures [Figures22 and and3].3]. Abscess was drained under anesthesia and the incision closed primarily with a suction drain. Pus culture revealed Staphylococcus aureus, sensitive to flucloxacillin, vancomycin, gentamicin, amikacin and ciprofloxacin. Stain for acid-fast bacilli was negative. Histopathology of the abscess wall showed features of pyogenic abscess with no evidence of tuberculosis. Patient improved with parenteral antibiotics and supportive care, without any residual disability. At 3-month follow-up, the patient remains symptom-free.