History and exam
Key diagnostic factors
common
presence of risk factors
Use of any potential triggering medication is a strong risk factor. Common medications implicated include antibiotics (particularly beta-lactams), non-steroidal 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.
oedema
Occurs with non-steroidal anti-inflammatory drug use due to a concurrent nephrotic syndrome that causes protein loss and hypoalbuminaemia.
decreased urinary volume
Occurs in some patients; however, most patients have non-oliguric acute kidney injury.
Other diagnostic factors
uncommon
arthralgia
May be present in some patients.
uveitis
Occurs as part of tubulo-interstitial 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, rifampicin, and a variety of fluoroquinolones), non-steroidal anti-inflammatory drugs, proton-pump inhibitors, and immune checkpoint inhibitors. Others include H2 antagonists (cimetidine and ranitidine), allopurinol, diuretics, phenytoin, mesalazine, 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 tubulo-interstitial nephritis with uveitis (TINU) syndrome.[4]
Use of this content is subject to our disclaimer