AKI Due to Henoch-Schonlein Purpura Following Exposure to Ciprofloxacin: A Rare Entity

Introduction: Ciprofloxacin is a broad-spectrum antibiotic effective in a wide variety of bacterial infections and is generally well-tolerated. Renal complications associated with the use of ciprofloxacin include allergic interstitial nephritis and crystal-induced acute tubular injury. Herein, we report a very rare case of ciprofloxacin-induced Henoch-Schonlein Purpura (HSP). Case Description: A 62-year-old woman with type 2 diabetes mellitus, hypertension and recurrent heel osteomyelitis presented from a Podiatry clinic to the hospital due to poor wound healing. She had completed 8 weeks of meropenem and had been switched to a course of ciprofloxacin and doxycycline 1 week prior to admission. On arrival, blood pressure was 140/69 mmHg, temperature 98.7 F, pulse 70, respirations 18/min. Labs showed an elevated ESR 118 mm/hr. A left foot x-ray was consistent with osteomyelitis. A left calcaneal wound culture grew methicillin-resistant Staphylococcus aureus and Corynebacterium striatum. Blood and urine cultures were negative. The patient was kept of ciprofloxacin and doxycycline on admission and then switched to intravenous vancomycin and cefepime. On hospital day 3, the patient developed a new purpuric skin rash distributed over upper and lower extremities, associated with gross hematuria. Labs revealed AKI with a serum creatinine (sCr) of 1.6 mg/dL (from 0.7). A skin biopsy revealed IgA granular deposition within the walls of superficial dermal vessels consistent with IgA vasculitis. Urine protein-to-creatinine ratio (UPCR) was 4.8 g/g. Urinary sediment microscopy revealed waxy casts, acanthocytes and RBC casts. A kidney biopsy was performed and it showed IgA nephropathy (M1 E0 S0 T1 C1), moderated diabetic nephropathy, and focal acute tubular injury. The patient was started on prednisone 30 mg/day. The skin lesions improved, sCr stabilized to 1.3 mg/dL. Unfortunately, the patient died 6 months later due to refractory osteomyelitis and sepsis. Discussion: Our patient abruptly developed IgA vasculitis (skin and kidney involvement) 2 days post completion of a 9-day course of ciprofloxacin. Ciprofloxacin-induced HSP is extremely rare. As of now, only 7 cases have been reported in PubMed-indexed medical journals. Thus, a high index of suspicion is required to recognize this potentially serious condition.