Acute Exacerbations


Acute Exacerbations in Idiopathic Pulmonary Fibrosis

People with idiopathic pulmonary fibrosis (IPF) are often concerned about having an acute exacerbation (AE). An AE is an episode of significant worsening in lung function that is not caused by heart failure or fluid overload in the lungs.

In medical terminology, the word “acute” means “happens suddenly and requires urgent care”. The word “exacerbation” means “worsening disease”. 

People experiencing an AE usually have a rapid onset of marked breathlessness, coughing, and fatigue. Sometimes they have a fever. They often feel very ill.

AEs are extremely serious. Studies have found that approximately half of patients with an AE requiring hospitalization will not survive to discharge.1

How common is an acute exacerbation (AE) in people with IPF?

In a year, approximately 5 to 15 out of every 100 people with IPF will have an AE.2

How is an AE diagnosed?

There are four criteria that must be met for a physician to diagnose an AE1:

  1. The person has a diagnosis of IPF (or a new diagnosis of IPF must be made when the person with the AE visits the doctor because of the symptoms of the AE).
  2. Marked worsening in breathlessness that has lasted typically less than one month.
  3. A computed tomography (CT) scan showing a pattern of lung damage and inflammation called “ground-glass opacity and/or consolidation”. This pattern must also be seen along with the typical patterns on the scan that show IPF, which are called patterns of “usual interstitial pneumonia”.
  4. The worsening in lung function is not explained by heart failure or fluid overload in the lungs. 

What causes an AE?

There are two types of AEs, triggered and untriggered.3

Triggered AEs can be caused by:

  • Infection in the lungs, such as influenza, cold viruses, pneumonia-causing bacteria, or herpes virus
  • Inhaling stomach acid into the lungs, such as happens with gastroesophageal reflux disease (GERD)
  • Air pollution
  • Having a surgery with anesthesia, which can cause stress to the lungs
  • Drug toxicity from chemotherapy or immunosuppressive therapy

Untriggered AEs have no known cause that doctors can identify. These may be caused by a quickening of the IPF disease process itself.

What are risk factors for AEs?

Not every person with IPF who has an infection, GERD, surgery, or exposure to air pollution experiences an AE. Some people are more susceptible than others. Researchers are working to understand what makes people with IPF more or less susceptible to having and AE. One common finding is that the worse lung function as assessed by spirometry becomes, the more the risk of having an AE increases.4 Having a previous AE increases the risk of having another AE.1

Other factors that may increase risk are smoking, being male, having untreated GERD (reflux), and higher body mass index (BMI).1 Researchers are still studying these factors.

How is an AE treated?

AEs are extremely serious and require admission to the hospital. Antibiotics are usually given, in case there is a bacterial infection that might have triggered the AE. Supportive care measures, such as oxygen and management of symptoms, are always given.

Historically, AEs have been treated with corticosteroids (prednisone). Corticosteroids can lessen inflammation, so it was thought this might help during an AE. However, this has recently been called into question. A study from 2019 conducted in San Francisco, California looked at medical records from 82 patients with IPF who were admitted to the University of California, San Francisco medical center with an AE. Of those 82 patients, 37 received corticosteroids and 45 did not. Those patients who received corticosteroids were more likely to require ICU level care and mechanical ventilation and had a shorter overall survival.The corticosteroids appeared in this study to do more harm than good.

Researchers are actively studying treatments for AEs.6 Some of the interventions being studied include high flow oxygen therapy7, polymyxin B-immobilized fiber cartridges to filter patient blood8, and the medications tacrolimus9 and cyclosporine10. Results have been mixed or are preliminary. Treatment guidelines for AE do not suggest using any of these experimental therapies outside of a clinical trial.11

How can I reduce the risk of an AE?

Specialists in the field of IPF suggest the following to reduce the risk of an AE2:

  • Annual influenza vaccination (and pneumococcal vaccination when suggested by a doctor)
  • Handwashing and avoiding people with contagious respiratory illnesses
  • Treatment for GERD, if present
  • Tell doctors and anesthesiologists about the IPF diagnosis before having a surgery


  1. Collard HR, Ryerson CJ, Corte TJ, et al. Acute exacerbation of idiopathic pulmonary fibrosis. An International Working Group ReportAm J Respir Crit Care Med. 2016;194(3):265-275.
  2. Johannson K, Collard HR. Acute exacerbation of idiopathic pulmonary fibrosis: a proposalCurr Respir Care Rep. 2013;2(4):10.1007/s13665-013-0065-x.
  3. Ryerson CJ, Cottin V, Brown KK, Collard HR. Acute exacerbation of idiopathic pulmonary fibrosis: shifting the paradigmEur Respir J. 2015;46(2):512–520. 
  4. Qiu M, Chen Y, Ye Q. Risk factors for acute exacerbation of idiopathic pulmonary fibrosis: A systematic review and meta-analysisClin Respir J. 2018;12(3):1084–1092. 
  5. Farrand E, Vittinghoff E, Ley B, et al. Corticosteroid use is not associated with improved outcomes in acute exacerbation of IPFRespirology. 2019;10.1111/resp.13753. doi:10.1111/resp.13753
  6. Juarez MM, Chan AL, Norris AG, Morrissey BM, Albertson TE. Acute exacerbation of idiopathic pulmonary fibrosis-a review of current and novel pharmacotherapies. J Thorac Dis. 2015;7(3):499–519.
  7. Vianello A, Arcaro G, Molena B, et al. High-flow nasal cannula oxygen therapy to treat acute respiratory failure in patients with acute exacerbation of idiopathic pulmonary fibrosisTher Adv Respir Dis. 2019;13:1753466619847130. 
  8. Enomoto N, Mikamo M, Oyama Y, et al. Treatment of acute exacerbation of idiopathic pulmonary fibrosis with direct hemoperfusion using a polymyxin B-immobilized fiber column improves survivalBMC Pulm Med. 2015;15:15. 
  9. Horita N, Akahane M, Okada Y, et al. Tacrolimus and steroid treatment for acute exacerbation of idiopathic pulmonary fibrosisIntern Med. 2011;50(3):189–195. 
  10. Aso S, Matsui H, Fushimi K, Yasunaga H. Effect of cyclosporine A on mortality after acute exacerbation of idiopathic pulmonary fibrosisJ Thorac Dis. 2018;10(9):5275–5282. 
  11. Somogyi V, Chaudhuri N, Torrisi SE, et al. The therapy of idiopathic pulmonary fibrosis: what is next? Eur Respir Rev. 2019;28(153):190021.