Infection and Drug Associated Tubulointerstitial Nephritis and Acute Tubular Necrosis in a Presentation Similar to That of Post-Streptococcal Glomerulonephritis: A Case Report.

Tubulointerstitial nephritis (TIN) is an inflammatory infiltrate of interstitial kidney most commonly caused by infections, drugs, allergies, and a number of autoimmune conditions. In this case, we have a 40-year-old male who was thought to have post-streptococcal glomerulonephritis given his symptoms of sore throat and pharyngitis before having renal involvement; however, after further evaluation was found to have biopsy proven interstitial nephritis without glomerular involvement. We note that TIN has multiple etiologies, and in our patient, we believe the combination of sore throat and pharyngitis attributed to Streptococcus pyogenes and the concomitant nonsteroidal anti-inflammatory drug use and eventual bacterial translocation into the bloodstream, led to all the atypical manifestations described in this study. Although TIN is diagnosed definitively through biopsy, it is not able to reveal the specific causes especially when there are multiple causes suspected simultaneously. Such situations may be challenging to pinpoint a cause therefore it is of utmost importance to keep a broad differential for unexplained acute kidney injury.