Full-house Membranous Nephropathy in a Case of Primary Sjögren's Syndrome: A Lion's Mane on a Lamb

Primary Sjögren’s syndrome is a systemic autoimmune condition affecting primarily the exocrine glands, with an incidence rate of 6.92 per 100,000 person-years (95% CI 4.98 to 8.86). Initial presentation of this disease varies widely, depending on the level of systemic involvement. Renal involvement remains a concern in affected patients with a recent study showing almost a 5% rate of the same, although specifics remain difficult to characterise. This diversity of symptoms makes it difficult to finally diagnose patients with Sjögren’s syndrome. This case report emphasises the importance of a thorough clinical history and investigations in diagnosing primary Sjögren’s syndrome. The initial presentation was non-specific generalised weakness due to hypokalaemia, while the renal biopsy in the end even pointed towards possible lupus nephritis further complicating the clinical picture. Such diverse and often overlapping manifestations underscore the diagnostic challenges associated with Sjögren’s syndrome.