Abstract
BACKGROUND: Whipple's disease, caused by Tropheryma whipplei, is a rare multisystem infectious disorder with diverse clinical manifestations. Typical symptoms include arthralgia, nausea, vomiting, diarrhoea, and weight loss, while nonspecific features such as fever, anaemia, and lymphadenopathy may also occur. Presentations with multiple serous effusions are exceedingly rare. Diagnosis remains particularly challenging in resource-limited regions because of nonspecific symptoms and limited access to advanced diagnostic techniques. CASE PRESENTATION: A 34-year-old male presented with fever, vomiting, diarrhoea, mild dry cough, and anorexia. Whole-body computed tomography revealed systemic inflammatory changes that mimicked vasculitis, including multiple serous effusions (pleural, peritoneal, pericardial, and pelvic) and omental thickening. Initial anti-infective therapy failed. Serological tests, pleural fluid analysis, and thoracoscopic pleural biopsy excluded systemic vasculitis and pleural malignancy. Given the diagnostic uncertainty, subsequently 18F-fluorodeoxyglucose positron emission tomography demonstrated diffuse peritoneal thickening accompanied by hypermetabolism, which prompted a biopsy. Definitive diagnosis was achieved via laparoscopic omental biopsy with histopathology, periodic acid-Schiff staining, and polymerase chain reaction. Despite receiving targeted antibiotic therapy for T. whipplei, the patient showed suboptimal clinical improvement. We speculated that the recurrence of the patient's condition was more likely attributable to immune reconstitution inflammatory syndrome. Combination therapy with doxycycline, hydroxychloroquine, and short-term glucocorticoids induced sustained remission. After more than 2 years of targeted anti-T. whipplei therapy, the patient demonstrated a favourable recovery. CONCLUSIONS: Multiple serous effusions are uncommon clinical manifestations of Whipple's disease. Early identification of T. whipplei infection and timely targeted therapy are critical for improving patient prognosis.