Community-acquired Acinetobacter pneumonia associated with Evans syndrome: a case report.

Introduction and importance: Acinetobacter baumannii, a gram-negative bacterium, is a rare cause of community-acquired pneumonia (CAP), especially concerning immunocompromised individuals due to its resistance to multiple antibiotics. It typically presents with fever, productive cough, and shortness of breath, and is associated with high morbidity and mortality. In patients with underlying conditions like Evans syndrome (ES), the management becomes even more challenging. ES is a rare autoimmune disorder characterized by immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia (AIHA), which significantly alters the immune response and increases susceptibility to infections. Case presentation: We present the case of a 19-year-old male with a history of ES who developed severe CAP caused by Acinetobacter baumannii. The patient exhibited fever, shortness of breath, and productive cough, with clinical findings of tachycardia, hypotension, pallor, and abnormal laboratory results, including hemolytic anemia and severe thrombocytopenia. Despite initial antibiotic treatment, the infection persisted until polymyxin, effective against multidrug-resistant A. baumannii, was introduced. Imaging studies confirmed bilateral lung infiltrates, and the infection exacerbated the patient's ES, complicating the clinical scenario. Clinical discussion: This case highlights the increasing role of A. baumannii in CAP, particularly in immunocompromised patients, and underscores the importance of timely, targeted treatment. A dual approach involving antibiotics for the infection and corticosteroids for the autoimmune disorder proved crucial for stabilization. Conclusion: Multidisciplinary care is essential in managing such complex, multifactorial cases. The case emphasizes the need for a collaborative approach involving infectious disease and immunology specialists to improve patient outcomes.