Rare respiratory infections as causes of reactive arthritis

Abstract

Reactive arthritis (ReA) is an immune-mediated, aseptic arthritis that may develop within a period ranging from 3 days to 6 weeks following any extra-articular infection. Although it is most commonly precipitated by gastrointestinal or genitourinary infections, in the aftermath of the SARS-CoV-2 pandemic, increasing attention has been directed toward the role of respiratory pathogens in the development of this condition. Accordingly, the aim of this review is to present current knowledge regarding rare respiratory pathogens associated with ReA, with particular emphasis on their clinical relevance and diagnostic and therapeutic implications. A systematic search of the relevant scientific literature was conducted using the Medline database, with a particular focus on the period from 2020 to 2025, in order to identify and analyze cases of ReA occurring in the context of respiratory infections, primarily those caused by rare respiratory pathogens. The analysis included individual case reports, original research articles, and review papers documenting the occurrence of ReA following respiratory infections. The most frequently identified respiratory pathogens were SARS-CoV-2, Chlamydophila pneumoniae, Streptococcus pyogenes, Parvovirus B19, and Mycoplasma pneumoniae, with a variable time interval between infection and the onset of arthritis (ranging from several days to several weeks). Less common respiratory pathogens included Streptococcus pneumoniae, Neisseria meningitidis, Rothia mucilaginosa, Haemophilus influenzae, and Mycobacterium tuberculosis. The clinical presentation of ReA associated with these pathogens did not differ substantially from that of typical etiologies; however, differences were observed in symptom duration and therapeutic response. In most cases, arthritis was oligoarticular, asymmetric, and accompanied by systemic signs of inflammation. Therapeutic approaches included nonsteroidal anti-inflammatory drugs, corticosteroids, and, in selected cases, antibiotics and immunosuppressive agents. ReA triggered by rare respiratory pathogens represents a diagnostic challenge. Although these pathogens are less frequently identified, their role in the etiopathogenesis of ReA warrants additional attention, given the potential for an atypical disease course and the need for individualized therapeutic strategies. The limited number of available case reports and other scientific publications highlights the need for further research and for the standardization of diagnostic criteria in this field.