• Acute interstitial nephritis is a kidney or renal dysfunctioning condition where being affected by it can rapidly decline the renal functioning.
  • The word itself describes the nature of the disease and the term “Acute” denotes the sudden onset of disease with less than 3 months of duration , “Interstitial” denotes the surrounding area or tissue around the nephron ,”Nephritis” denotes inflammation to the nephron /

surrounding regions of the kidney .




The majority of the disease can happens due to long-term use of


I.Medications such as 


Almost two thirds of cases are due to long-term use of medication 

  • Hypersensitivity drugs 
  • Antibiotics such as beta lactams,quinolones,cephalosporins,fluoroquinolones etc
  • NSAIDS (Ibuprofen)
  •  Proton pump inhibitors (pantoprazole)
  • Diuretics (Furosemide,Thiazides)
  • Allopurinol
  • Phenytoin




  • 10-15% of cases have infections as underlying cause 
  • Attack from microorganisms such as E.coli,campylobacter,salmonella, streptococcus
  • Viral infections Such as measles ,mumps ,HIV,CMV,EBV
  • Fungal infections by histoplasmosis ,coccidiomycosis 
  • Protozoal infections such as toxoplasmosis

III.Systemic conditions


  • It accounts for 10-15% of cases 
  • Systemic or immune diseases such as sjogren’s syndrome ,lupus and sarcoidosis
  • 10-20% of Acute kidney injury is due to Acute interstitial nephritis 




  • 5-10% of cases have unknown etiology
  • Diseases such as Anti-TBM,TINU syndrome


V.Too little potassium in blood (or) Too much calcium/uric acid in blood .


Clinical features


  • Asymptomatic
  • Non-oliguric Acute kidney injury 
  • Nausea ,vomiting 
  • Malaise
  • Flank pain 
  • Frequent urination 
  • Swelling of feet 
  • Pain or burning sensation during urination 


Specific symptoms 


  • Drug induced- Acute interstitial nephritis has a classic triad in almost 10% cases


  • Skin rash
  • Low -grade fever 
  • Eosinophilia 


  • Infections 


  • Fever 
  • More specific infections to underlying infection or illness                                             




  • In Drugs induced AIN , medications acts as haptens /proteins which binds to tubular cells to initiate a immune response 
  • May be for several weeks to months 


  • In infections induced AIN, Microorganisms antigens gets deposited in to interstitium which activates the immune response which on mediation can damage the kidneys




  • Urinalysis
  • Blood test
  • Kidney biopsy is recommended for definitive diagnosis or for patients who are not responding even after withdrawal of the drugs or managing underlying conditions 
  • But biopsy is contraindicated in bleeding diathesis, solitary kidney,ESRD, Uncontrolled Hypertension,sepsis 
  • Imaging studies such as Renal ultrasonography can be used to study the increased or decreased size 


Lab findings  


  • Sterile pyuria
  • Leukocyte / WBC casts 
  • Proteinuria- subnephrotic stage
  • Microscopic Hematuria casts ,rare
  • Renal tubular 
  • Peripheral eosinophilia 
  • Eosinophiluria-predictive value of 38% is positive 
  • Serum creatinine profile -elevated BUN and creatinine suggest variable degree of renal injury 
  • Hyper /hypokalemia ,hyperchloremic metabolic acidosis suggest tubulointerstitial injury
  • Fractional excretion of sodium (>1%)
  • Elevated transaminase levels in drug induced injuries  




  • Supportive care 
  • Withdrawal of drugs and substitute with alternative drugs 
  • Managing fluid and electrolyte balance and hydration
  • Removing the underlying etiology 
  • Corticosteroids should be initiated early which can results of recovery within 2 hours 
  • Prednisone -1mg/kg,orally -2 to 3 weeks followed by gradually tapering dose over 3-4 weeks 
  • If not responded , cyclophosphamide is considered 
  • In situations of severe damage to kidneys dialysis is considered 




  • Patients who discontinue medications can recover within 2 weeks of onset and more likely to recover than those who remained continuing for more than 3 or 4 weeks 
  • Adverse prognostic factors include inflammation occurring diffusely on biopsy ,elevated number of neutrophils,severity of interstitial fibrosis.
  • There is a good prognostic value otherwise 


Frequently asked questions 


1.Is Acute interstitial nephritis serious?


  • It is serious but can be treated if identified early 
  • In AIN, spaces between the nephrons get inflamed and reduce the functional ability of kidneys to filter.
  • And in few cases they may end up in kidney failure 


2.What usually causes Acute interstitial nephritis?


  • Usually allergic reactions to medicated drugs and infections or other idiopathic conditions can cause acute interstitial nephritis


3.How does Acute interstitial nephritis feel like?


  • Can range from mild to moderate or even severe kidney problems
  • In almost half of the cases there is a decreases urine output and signs of acute kidney failure 
  • The symptoms include nausea ,vomiting malaise,flank pain,edema etc


4.How is Acute interstitial nephritis diagnosed ?


  • Some suggest renal biopsy but not  every patients should undergo this diagnostic test
  • In few biopsy with histopathological findings shows plasma cells and lymphocytic infiltrates in the peritubular areas of interstitium with edema 
  •  other tests include urine analysis also provide the evidence 


5.Is Acute interstitial nephritis reversible?


  • It totally depends upon the etiological cause 
  • In infection induced or idiopathic reasons then the disease is reversible
  • If drug induced(NSAIDs) then there is a chance of permanent insufficiency in almost 40% of cases 


6.What medications can cause nephritis?


  • NSAIDS , Antibiotics, anti-inflammatory drugs and proton pump inhibitors


7.Can nephritis be cured 


  • May not be cured ,but can be treated as mentioned earlier
  • Proper treatment can keep the condition on track and protect the kidneys
  • It is important to follow the expert advice and instructions
  • If kidney failure occurred there is no other way except undergoing dialysis or Transplantation


8.Does nephritis cause fatigue ?


  • Yes,toxins ,metabolites does not filter properly into the urine instead ,build up in body causing swelling and fatigue 


9.Can UTI cause nephritis


  • Yes,Infections can spread from urinary tract to kidneys
  •  It can result in acute or even chronic Interstitial nephritis


10.Complications of Acute Interstitial nephritis


  • Hypertension
  • Increased levels of cholesterol
  • Chronic kidney disease or failure 


11.What type of Hypersensitivity is acute interstitial nephritis


  • It is a drug Hypersensitivity reaction or DHR
  • can be manifested in a week or 2 after exposure to certain drugs 


12.Does Acute interstitial nephritis cause Acute kidney injury?


  • Classically Acute interstitial nephritis presents as acute kidney injury after the use of drugs or underlying systemic  infections and sometimes often associated with pyuria,hematuria , proteinuria


13.Does Interstitial nephritis cause proteinuria?


  • Not always but can cause proteinuria ranging from moderate to heavy proteinuria due to cytokine like permeability increasing factor secreted by inflammatory cells


14.Is Acute interstitial nephritis hereditary?


  • The inheritance of one mutated gene from an affected parent can lead to disease
  • Disease is autosomal -dominant conditions half of the offspring will have a chance of disease 


15.What is allergic interstitial nephritis?


  • It is one of the commonest form of acute interstitial nephritis 
  • The reason includes exposure to drugs 


16.Does Acute interstitial nephritis cause pain ?


  • If the cause of pyelonephritis ,symptoms of fever ,nausea ,vomiting and lower back pain is most common 


17.What medications help kidney function?


  • Angiotensin renin blockers and Angiotensin converting enzymes inhibitors decrease blood pressure and slow down the loss of kidney function 
  • Additionally they delay the progression of kidney failure


18.What fruits are great for kidneys?


  • Pineapple ,grapes ,cranberries and apples are known to have known  anti Inflammatory property and helps to heal, benefit the kidney health


19.How do you treat acute interstitial nephritis naturally?


  • 2 teaspoons of crushed parsley juice with 1 spoon of honey consumed 3 times daily  can improve the condition
  • 1 glass of carrot juice + 1 tablespoon of lemon juice and honey consumed once daily for everyday during mornings on early stomach is another proven ayurvedic remedy 


20.Natural diet which improves kidney health?


  • As coconut water is an excellent diuretic ,while consuming 2 glasses of  it daily can benefit  
  • Including bananas around 3-5 and 1 papaya in your diet.


Back to Top