Piriformis pyomyositis: a report of three cases

Staphylococcus aureus Bacteremia With Disseminated Multiple Foci and Pyomyositis in an Immunocompetent Patient: A Case Report

Pyomyositis is an uncommon primary infection of skeletal muscle resulting in muscle inflammation followed by pus formation. Pyomyositis is typically caused by Staphylococcus aureus (S. aureus), and most cases are associated with skin penetration and/or immunosuppressive conditions in tropical or even temperate climates. We report a previously healthy, immunocompetent 44-year-old man who presented with fever and right lower back pain. He had received an analgesic injection for his back pain 12 days prior to this visit. His clinical course was further complicated by the coexistence of multiple muscular abscesses, renal infarction, and septic arthritis of the right shoulder. He underwent computed tomography-guided drainage of the abscess. The abscess and blood cultures were positive for methicillin-susceptible S. aureus. The patient responded well to prolonged treatment with cefazolin and cephalexin and was discharged 12 weeks after initial admission.

Bilateral thigh pyomyositis in an otherwise healthy middle-aged woman: A case report

BACKGROUND

Pyomyositis generally occurs in otherwise healthy young men. Because this condition is unusual among otherwise healthy women in temperate climates, we present the following case.

CASE SUMMARY

An otherwise healthy 43-year-old woman presented with bilateral pain in her lower extremities and fever. Magnetic resonance imaging (MRI) findings were indicative of myositis with a possible abscess. We initiated empirical antibiotic therapy with ceftriaxone. However, the swelling and pain in her legs persisted even after 7 d of treatment. Contrast MRI revealed multiple pockets of pus in the vastus lateralis and gluteal muscles. We performed needle aspiration of these abscesses with ultrasound guidance and local anesthesia. Upon culturing, the purulent material was positive for Staphylococcus aureus. We diagnosed her with S. aureus-induced pyomyositis of the vastus lateralis muscle and gluteus region. Based on the antibiotic sensitivity report, ceftriaxone was administered for an additional 7 d. By day 15 post-drainage, the patient was able to start walking. Oral antibiotic therapy was continued for 1 wk following her discharge from hospital, after which her symptoms resolved completely.

CONCLUSION

Pyomyositis may present with muscle pain, swelling, and fever. Ultrasound-guided percutaneous puncture and drainage may enable timely diagnosis and treatment.

Pyomyositis of the Piriformis Muscle—A Case of Piriformis Syndrome

Piriformis syndrome is a rare cause of sciatica, which results in low backache due to sciatic nerve compression. This syndrome is associated with abnormalities in the piriformis muscle, which cause sciatic nerve entrapment, like anatomical variations, muscle hypertrophy, and inflammation. It can also result from the abnormal course of sciatic nerve itself through normal piriformis muscle. Piriformis syndrome due to pyomyositis of the piriformis muscle is extremely rare and only 23 cases are reported in literature. Herein, we report one such rare case of a patient, with pyomyositis of piriformis muscle, who presented with piriformis syndrome.

Piriformis Pyomyositis Presenting as Migratory Hip to Knee Pain: A Case Report

CASE

The authors report a case of piriformis pyomyositis in a teenage female patient with fever and left hip pain. Her pain migrated to the knee with concurrent near resolution of hip pain. Imaging revealed an abscess in the left piriformis with pus tracking along the sciatic nerve sheath. This was complicated by internal iliac vein thrombosis and an embolus to the lung. Open drainage was performed, followed by outpatient intravenous cloxacillin and oral warfarin, with complete resolution of symptoms.

CONCLUSION

Piriformis pyomyositis is a rare condition with varying presentations. The threshold for suspicion should be low even in healthy young individuals.

Piomiosite do piriforme em um paciente com doença de Kikuchi-Fujimoto—relato de caso e revisão da literatura

Primary pyomyositis is a deep bacterial infection of the skeletal muscle. If left undiagnosed and untreated, the infection spreads, leading to sepsis, septic shock, and even death. The authors report a 23-year-old female presenting with piriformis pyomyositis during a treatment for Kikuchi–Fujimoto disease. Pyomyositis is a rare but potentially severe infection, which can lead to septic shock. The present case shows the need for a high degree of clinical suspicion for patients with compromised immune systems to begin treatment at an early stage. The literature demonstrates that outcomes of the treatment of piriformis pyomyositis are good.

Sciatica caused by pyomyositis of the piriformis muscle in a pediatric patient

Because the sciatic nerve leaves the pelvis through the greater sciatic notch underneath the piriformis muscle, any pathology of the piriformis muscle could result in entrapment of the sciatic nerve; this is widely known as piriformis muscle syndrome. Pyomyositis of the piriformis muscle may be a cause of piriformis muscle syndrome. Piriformis muscle syndrome caused by pyomyositis of the piriformis muscle in pediatric patients is rare. This article describes a case of sciatica caused by pyomyositis of the piriformis muscle in a pediatric patient. A 6-year-old boy presented with right buttock and thigh pain following a mild fever and sore throat. The pain worsened, and he became unable to walk. On admission, his temperature was 38.4°C. He reported severe right-sided buttock and lateral thigh pain. Positive Freiberg sign was observed. Laboratory examination revealed elevated white blood cell count and C-reactive protein level. T2-weighted magnetic resonance images of the pelvis revealed high-intensity changes of the piriformis muscle and iliosacral joint. Thus, piriformis syndrome caused by pyomyositis of the piriformis muscle was diagnosed. Oral antibiotics (10 mg/kg per day of cefdinir) were administered. Pain gradually decreased, and the patient was able to walk. Final follow-up examination at 6 months after symptom onset revealed no sciatic pain. Follow-up magnetic resonance imaging revealed normalized intensities of the piriformis muscle. The endopelvic fascia provides a route for infection from the pelvis to the piriformis. The pyomyositis of the piriformis muscle in the current case may have occurred secondary to the pyoarthritis of the sacroiliac joint. Endopelvic infections involving the piriformis muscle may mimic hip diseases in pediatric patients.

The conservative management of primary pyomyositis abscess in children: case series and review of the literature

Pyomyositis is a primary pyogenic infection in skeletal muscle, often progressing to abscess formation. It is rare in temperate climates and generally deep-seated within the pelvis with nonspecific clinical features, making diagnosis difficult. Magnetic resonance imaging (MRI) is highly sensitive for muscle inflammation and fluid collection, and with its increasing availability is now the investigation of choice. Treatment of pyomyositis abscess has traditionally been with incision and drainage or guided aspiration followed by a prolonged course of antibiotics, although there are sporadic reports of cases treated successfully with antibiotics alone. Our aim was to describe our own experience with the treatment of pyomyositis abscess in children. From our 20-year database of over 16,000 paediatric orthopaedic admissions, we identified only three cases with MRI-confirmed pyomyositis abscess. These were all in boys (aged 2-12 years) and affected the gluteal, piriformis and adductor muscles. Despite the organisms not being identified, each patient was treated successfully with a short (4-7 days) course of intravenous antibiotics followed by 2-6 weeks of oral therapy. There were no recurrences or complications and all made a full recovery. In conclusion, we propose that uncomplicated pyomyositis abscess in children may usually be managed conservatively without the need for open or percutaneous drainage.