Interstitial nephritis is most commonly caused by which of the following?

Interstitial nephritis is most commonly caused by which of the following?

• A. Autoimmune disease
• B. Drug-induced reaction
• C. Bacterial infection
• D. Vascular injury

Answer: (B)

Drug-induced hypersensitivity is the most common cause of interstitial nephritis. Certain medications trigger an immune-mediated inflammation in the renal interstitium, leading to acute kidney injury. Common culprits include antibiotics such as penicillins, cephalosporins, and sulfonamides, rifampin, NSAIDs, and some proton pump inhibitors. This reaction usually occurs days to weeks after starting the drug and may present with fever, rash, eosinophilia, and eosinophiluria or sterile pyuria on urinalysis. The kidney damage comes from interstitial inflammation with eosinophils and T cells rather than from primary glomerular disease. The key management step is stopping the offending medication, which often leads to recovery; corticosteroids may be used if renal function does not improve promptly. Although autoimmune causes can occur, and bacterial infections or vascular injury can affect the kidneys, drug-induced hypersensitivity remains by far the most common cause of this pattern of interstitial inflammation.

Drug-induced hypersensitivity is the most common cause of interstitial nephritis. Certain medications trigger an immune-mediated inflammation in the renal interstitium, leading to acute kidney injury. Common culprits include antibiotics such as penicillins, cephalosporins, and sulfonamides, rifampin, NSAIDs, and some proton pump inhibitors. This reaction usually occurs days to weeks after starting the drug and may present with fever, rash, eosinophilia, and eosinophiluria or sterile pyuria on urinalysis. The kidney damage comes from interstitial inflammation with eosinophils and T cells rather than from primary glomerular disease. The key management step is stopping the offending medication, which often leads to recovery; corticosteroids may be used if renal function does not improve promptly. Although autoimmune causes can occur, and bacterial infections or vascular injury can affect the kidneys, drug-induced hypersensitivity remains by far the most common cause of this pattern of interstitial inflammation.