A Rare Case of Renal Crisis in Systemic Sclerosis–Systemic Lupus Eritematosus Overlap Syndrome: A Case Report and Literature Review

We present a patient with systemic sclerosis–systemic lupus eritematosus (SSc-SLE) overlap syndrome who was initially diagnosed as SLE. The patient underwent kidney biopsy and was diagnosed as SSc renal crisis as a result of the biopsy. With this case, we aimed to raise awareness about renal crisis in limited scleroderma cases. We present a rare case of renal crisis in a 49-year-old male patient with limited SSc-SLE overlap syndrome. The patient, who applied to the rheumatology clinic with complaints of bruising on the fingers and toes, weight loss, and swelling in the legs, was diagnosed with SLE in April 2022. Renal function tests were normal at that time. About 2 months after this diagnosis, he applied to the emergency department of our hospital with complaints of shortness of breath and chest pain. He was admitted to our clinic because his blood pressure was 160/100 mmHg and his creatinine (cre) value was 3.8 mg/dl. We detected SSc renal crisis as a result of kidney biopsy performed in our patient with marked sclerodactyly. The patient was diagnosed with a rare coexistence of limited SSc and SLE. Renal crisis in limited SSc is a rare condition. Our patient is still dialysis dependent. In SSc-SLE overlapping patients presenting with renal failure, the picture may be associated with SSc kidney crisis, lupus nephritis, or a coexistence of kidney crisis and lupus nephritis. The differential diagnosis of renal involvement of SSc-SLE overlap syndrome is a challenging clinical management. Renal crisis is rare, especially in limited SSc. However, renal crisis must be kept in mind in the differential diagnosis who has resistant hypertension and SSc skin findings even though other signs of SSc are subtle.