Tropical Pyomyositis of Atypical Etiology: A Case Report

Abstract

Introduction: Tropical pyomyositis is a bacterial infection of the skeletal muscle caused by Staphylococcus aureus in 90% of cases. The most predisposed patients are those who are immunocompromised. Case Report: A 58-year-old male patient with a history of malignant prostate cancer undergoing treatment with hormonal therapy and radiotherapy, went to the emergency room for presenting, 1 week prior to admission, fever of 39°C associated with pain of progressive appearance located in the supracondylar region of the right lower limb, radiating to the inguinal region, of moderate to strong intensity, of an oppressive nature, which limited the movement of the entire right lower limb. After multiple negative tests, an MRI of the abdomen, pelvis, and lower limbs reported myositis of infectious etiology. From there, the relevant antibiotic treatment was indicated, and an ultrasound-guided biopsy of the iliopsoas muscle was performed, which reported Streptococcus agalactiae resistant to ampicillin and penicillin as the responsible pathogen. The evolution of the patient was favorable. Conclusions: Tropical pyomyositis is a disease little known by the medical community, which makes early diagnosis difficult. Immunosuppression plays an important role in its pathogenesis, so a thorough investigation must be carried out to exclude multiple predisposing conditions.