History and exam
Key diagnostic factors
common
use of triggering medication
Use of any potential triggering medication is a strong risk factor. Common medications implicated include antibiotics (particularly beta-lactams), nonsteroidal anti-inflammatory drugs, diuretics, proton-pump inhibitors, and immune checkpoint inhibitors.[8] Over 250 triggering medications are known.[10]
loss of kidney function
A history of acute or subacute loss of kidney function is usually the presenting feature. This develops over several days to weeks, and in the case of drug-induced AIN may develop several months after exposure to the inciting agent.[1]
uncommon
fever
The classical triad of fever, skin rash, and eosinophilia is found in less than 10% of patients.[4]
Mild pyrexia may be seen but is often not helpful.
rash
The classical triad of fever, skin rash, and eosinophilia is found in less than 10% of patients.[4]
A macular or maculopapular rash may be seen.
edema
Occurs with nonsteroidal anti-inflammatory drug use due to a concurrent nephrotic syndrome that causes protein loss and hypoalbuminemia.
decreased urinary volume
Occurs in some patients; however, most patients have nonoliguric acute kidney injury.
Other diagnostic factors
uncommon
arthralgia
May be present in some patients.
uveitis
Occurs as part of tubulointerstitial nephritis with uveitis (TINU) syndrome.
Risk factors
strong
use of a triggering medication
Over 250 medications are known to trigger AIN.[3][8][10] Common culprit medications include antibiotics (almost all penicillins and cephalosporins, many sulfonamides, rifampin, and a variety of fluoroquinolones), nonsteroidal anti-inflammatory drugs (NSAIDs), proton-pump inhibitors, and immune checkpoint inhibitors. Others include H2 antagonists (cimetidine and ranitidine), allopurinol, diuretics, phenytoin, mesalamine, and warfarin.[1][12]
weak
age >65 years
chronic inflammatory disease
AIN can occur in the context of sarcoidosis, Sjogren syndrome, IgG4-related syndrome, systemic lupus erythematosus, or tubulointerstitial nephritis with uveitis (TINU) syndrome.[4]
Use of this content is subject to our disclaimer