Abstract
Renal abscesses are rare in children. This report presents a case where a renal abscess due to methicillin-resistant Staphylococcus aureus (MRSA) was the initial indication of immunocompromised status in an adolescent boy. A 17-year-old male patient presented with a month-long history of fever, fatigue, and significant weight loss, along with dull aches and swelling in the left flank. There was no history of urinary symptoms, vomiting, or high-risk behaviors. His mother had died from sepsis while on antiretroviral therapy (ART), and his father from coronary artery disease. The patient had not been previously tested for human immunodeficiency virus (HIV). Examination revealed a tender fullness in the left lumbar region. Ultrasound showed a collection in the left kidney. Blood tests indicated anemia and elevated inflammatory markers. The patient tested positive for HIV antibodies. Empirical antibiotics were started. Ultrasound-guided aspiration grew MRSA, prompting a switch to vancomycin. A percutaneous catheter was inserted due to abscess recurrence. The patient received intravenous vancomycin followed by oral linezolid and started antiretroviral therapy. Repeat imaging at six weeks showed resolution of the abscess. Renal abscesses in children can be life-threatening and often result from urinary tract infections or hematogenous spread. This patient's abscess likely resulted from hematogenous spread due to immunocompromised status. Effective management, including prompt percutaneous drainage and targeted antibiotics, combined with ART, led to abscess resolution and a favorable outcome. This case underscores the importance of considering immunodeficiency in pediatric patients with unusual infections like renal abscesses and highlights the necessity of a multidisciplinary approach and aggressive management for complex infections in immunocompromised children.