Prolonged eosinophilia caused by Strongyloidiasis in a patient with rheumatoid arthritis treated with Upadacitinib

Abstract Rheumatoid arthritis (RA) is a systemic disease, which is caused by dysregulation of the immune system in the susceptible persons, making them immunocompromised and prone to infections during the course of their disease. The majority of RA patients are being treated with immunosuppressive drugs which render them even more immunocompromised. We present a Caucasian patient living in South-eastern Europe who developed prolonged eosinophilia during the treatment of RA with upadacitinib. After a comprehensive work-up she was diagnosed with Strongyloidiasis although living in non-endemic region of the world. We emphasize the importance of regular follow-up of immunocompromised patients and raise awareness of not only typical but also atypical infections which can occur during the course of the disease.