Introduction:

Rhupus syndrome is an uncommon but significant clinical condition, with an estimated prevalence rate of just 0.09% 1. Recognizing and understanding this disorder is crucial for effective diagnosis and treatment. “Rhupus,” or “Rhupus syndrome,” is a rare and overlooked condition that deserves greater attention. It is characterized by symptoms associated with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) in the same individual2. Despite its complexity, rhesus remains poorly understood, highlighting the necessity for further research and awareness in the medical community. It is a rare, neglected, incompletely understood, and thus debated condition that is commonly considered to feature the presence of symptoms of both SLE and rheumatoid arthritis (RA) in the same patient. Furthermore, psoriasis in the same patient creates a more challenging issue. It may be due to the similarity in genetic pathways between SLE & and Psoriasis, which may have made this co-existence3. Evidence also presents that paradoxically treating psoriatic patients with DMARD may result in new autoimmune diseases4. We recently encountered an intriguing case involving a 24-year-old man who presented with a long-standing history of polyarthritis and distinct hyperpigmented skin lesions. Initially diagnosed with psoriatic arthropathy, further investigation unveiled a fascinating complexity of autoimmune conditions, hinting at the potential of rhupus or undifferentiated connective tissue disease (UCTD). Despite ongoing treatment for psoriasis, the patient wasn’t responding as expected, calling for deeper diagnostic exploration. After careful consideration and consultations among expert clinicians, it became evident that we were facing an overlap syndrome. While navigating the diagnostic maze between undifferentiated connective tissue disease and rhupus, the team came to a unanimous and hopeful conclusion: this is indeed rhupus. This report highlights the intricate diagnostic journey, the therapeutic strategies we explored, and the clinical challenges we faced while managing this unique patient.