Severe psoriasis presenting with rapidly progressive (crescentic) IgA-predominant glomerulonephritis

IgA nephropathy (IgAN) is commonly associated with psoriasis; however, psoriasis presenting with crescentic IgAN is uncommon. A 49-year-old man with erythrodermic psoriasis with arthritis and stage 2 chronic kidney disease presented to the emergency department with worsening peripheral oedema and difficulty breathing. The patient had been hospitalised previously for a psoriasis flare. He was found to have an acute kidney injury on chronic kidney disease and was diagnosed with crescentic IgA glomerulonephritis on his first hospitalisation. He was treated with corticosteroids and was discharged stable with a plan to start cyclophosphamide in the outpatient setting. On his current hospitalisation, cyclophosphamide was added to his corticosteroids. Crescentic IgAN is rare. Its management has been based largely on observational studies. Our case highlights the importance of starting combined corticosteroids and cyclophosphamide early in crescentic IgAN and that corticosteroid monotherapy is insufficient in controlling disease progression.