Reversible acute-on-chronic kidney injury complicating antibiotic dosing in group A streptococcal necrotizing fasciitis at a remote Indonesian hospital: a case report.

Necrotizing fasciitis is a surgical emergency in which delayed source control increases mortality, and concurrent severe renal impairment both disrupts antibiotic dosing and risks misclassification as irreversible failure. A 72-year-old woman presented to a remote Indonesian district hospital with 5 days of right lower-leg pain, swelling, bullae and purulent discharge after a clinic incision. Admission creatinine was 4.6 mg/dl, rising to 5.0 mg/dl (estimated glomerular filtration rate ~9), with leukocytosis; ultrasonography showed small echogenic kidneys indicating chronic kidney disease. Initially treated as bullous cellulitis, the lesion progressed; a pre-operative wound culture grew Streptococcus pyogenes. Creatinine recovered to 1.17 mg/dl by postoperative Day 4, identifying severe but reversible acute-on-chronic injury. Antibiotics dosed to the acute nadir risked relative under-dosing as function recovered. An acutely elevated creatinine during sepsis can overstate the true baseline; serial measurement is essential before labelling end-stage disease or anchoring antibiotic dosing to the nadir.