Concurrent Hydroxychloroquine-Induced Myopathy and Nephropathy in a Patient with SLE

Summary: Hydroxychloroquine (HCQ) is a mainstay in autoimmune disease management, but rare toxicities such as myopathy and nephropathy can complicate long-term use. We present a 63-year-old female with SLE and positive ANCA who developed progressive proximal muscle weakness, elevated CK, and declining renal function after years of HCQ therapy. Workup revealed vacuolar myopathy on muscle biopsy and biopsy-proven HCQ-induced nephropathy. The clinical picture was initially confounded by overlapping features of lupus and possible ANCA vasculitis. Discontinuation of HCQ, initiation of corticosteroids and IVIG, and multidisciplinary care led to gradual clinical improvement. This case underscores the importance of considering HCQ toxicity in patients with unexplained myopathy and renal dysfunction, especially in the setting of long-term use.