Differential Diagnosis for a 47-year-old Lady with Anaemia, Malar Rash, and Renal Impairment
- Single most likely diagnosis
- c Lupus nephritis: This is the most likely diagnosis given the combination of anaemia, malar rash (a characteristic butterfly-shaped rash across the cheeks), and renal impairment. These symptoms are classic for Systemic Lupus Erythematosus (SLE), and lupus nephritis is a common and serious complication of SLE, leading to renal impairment.
- Other Likely diagnoses
- b Membranous nephropathy: This is an immune-mediated disease that can cause renal impairment and is sometimes associated with autoimmune diseases like SLE, but it can also be primary. The presence of anaemia and renal impairment could fit, though the malar rash is less commonly associated directly with membranous nephropathy.
- a FSGS (Focal Segmental Glomerulosclerosis): While FSGS is a cause of renal impairment and can be primary or secondary to various conditions, it is less directly linked to the combination of anaemia and malar rash compared to lupus nephritis. However, it remains a consideration in the differential diagnosis for renal impairment.
- Do Not Miss diagnoses
- Vasculitis (e.g., ANCA-associated vasculitis): Although less likely, vasculitis can cause renal impairment, anaemia, and various rashes. Missing this diagnosis could be deadly due to the potential for rapid progression to severe renal failure and other organ damage.
- Goodpasture's syndrome: This rare autoimmune disease can cause renal impairment and anaemia, and while it typically presents with hemoptysis due to pulmonary involvement, it's a diagnosis that should not be missed due to its severity and potential for treatment with immunosuppression.
- Rare diagnoses
- Mixed Connective Tissue Disease: This disease combines features of lupus, scleroderma, and rheumatoid arthritis and can cause renal impairment, anaemia, and various rashes, including a malar rash.
- Sjögren's syndrome: Primarily known for causing dry eyes and mouth, Sjögren's can also have systemic manifestations, including renal impairment and potentially a malar rash, though this is less common.