Abstract
Hemorrhagic cystitis is a diffuse inflammatory disease of the urinary bladder associated with macrohematuria. Several cases of hemorrhagic cystitis caused by penicillin G have been reported in adults but not children. Here we describe the first pediatric case of clinically-diagnosed penicillin G-induced hemorrhagic cystitis. The patient was a 9-year-old boy with a ventricular septal defect, chromosomal abnormalities, and infective endocarditis caused by Abiotrophia defectiva. After approximately four weeks of penicillin G administration, he had a culture-negative major hemorrhage with a clot. The hematuria resolved one week after penicillin G discontinuation, and a drug lymphocyte stimulation test for penicillin G was positive. In conclusion, penicillin G can also induce hemorrhagic cystitis in children. When large doses of penicillin G are used for long periods in adults or children, the patient should be monitored for hemorrhagic cystitis.