Bronchiolitis obliterans

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2FDA treatments16Active trials75Specialists8Treatment centers3Financial resources

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UniteRare data is sourced from FDA.gov, ClinicalTrials.gov, Orphanet, OMIM, and NORD.
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Overview

Bronchiolitis obliterans (also called obliterative bronchiolitis or constrictive bronchiolitis) is a rare and serious lung disease that affects the smallest airways in the lungs, called bronchioles. In this condition, these tiny airways become damaged and inflamed, leading to scarring and narrowing that blocks airflow. This makes it progressively harder to breathe. The disease is sometimes referred to as 'popcorn lung' because it gained public attention after cases were linked to workers inhaling diacetyl, a chemical used in microwave popcorn flavoring. The most common symptoms include a persistent dry cough, shortness of breath (especially during physical activity), wheezing, and fatigue. These symptoms often develop gradually over weeks to months and tend to get worse over time. Bronchiolitis obliterans can occur after lung or bone marrow transplantation, after certain infections, or after exposure to toxic fumes and chemicals. In some cases, no clear cause is found. There is currently no cure for bronchiolitis obliterans. Treatment focuses on slowing the progression of the disease and managing symptoms. Options include inhaled corticosteroids, bronchodilators, immunosuppressive medications (especially in transplant-related cases), and oxygen therapy. In severe cases, lung transplantation may be considered. Early detection and treatment are important because the scarring in the airways is generally irreversible once it occurs.

Also known as:

Key symptoms:

Shortness of breath, especially with activityPersistent dry coughWheezingFatigue and low energyDifficulty exercising or being physically activeFeeling like you can't get enough airRapid breathingChest tightnessUnexplained weight lossFrequent respiratory infections

Clinical phenotype terms (16)— hover any for plain English
Airway obstructionHP:0006536Bronchiolitis obliteransHP:0011946Reduced FEV1/FVC ratioHP:0030877Reduced forced vital capacityHP:0032341Reduced forced expiratory volume in one secondHP:0032342Decreased forced expiratory flow 25-75%HP:0032359Respiratory tract infectionHP:0011947Nonproductive coughHP:0031246Decreased DLCOHP:0045051Ground-glass opacificationHP:0025179
Inheritance

Sporadic

Usually appears on its own, not inherited from a parent

Age of Onset

Variable

Can begin at different ages, from infancy through adulthood

Orphanet ↗NORD ↗

FDA & Trial Timeline

10 events
Apr 2026Expanded Hemodialysis Versus High-Volume Online Hemodiafiltration for Uremic Toxin Removal

Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran — NA

TrialNOT YET RECRUITING
Mar 2026A Preliminary Clinical Study on the Efficacy of Cyclophosphamide and Sirolimus Combined With VIC-1911 in Preventing Graft-versus-Host Disease After Haploidentical Stem Cell Transplantation in Children

Shanghai Jiao Tong University School of Medicine — PHASE1

TrialNOT YET RECRUITING
Mar 2026Evaluation of the Short-term Effectiveness of Spinal Manipulation to Treat Acute and Subacute Low Back Pain.

Centre Hospitalier Universitaire de Nīmes — NA

TrialNOT YET RECRUITING
Mar 2026Yogabased Movements for Primary Headaches (Migraine and/or Cluster Headache) - YOURHEAD

Karolinska Institutet — NA

TrialNOT YET RECRUITING
Mar 2026Plasma and Radiologic Biomarkers of Response to ECP in Lung Transplant Recipients With CLAD

Brian Keller

TrialNOT YET RECRUITING
Feb 2026Anrikefon vs Nalfurafine for Sleep Quality in Hemodialysis Patients With CKD-aP

Zhujiang Hospital — PHASE4

TrialNOT YET RECRUITING
Feb 2026A Prospective Study to Evaluate the Efficacy of Iovera Lumbar Medial Branch Cryoneurolysis Versus Radiofrequency Ablation for the Treatment of Chronic Low Back Pain

Montefiore Medical Center — NA

TrialRECRUITING
Jan 2026Entecavir With or Without Pegylated Interferon α-2b in Children Aged 3-6 Years With Immune-Active Chronic Hepatitis B

Qing-Lei Zeng — PHASE4

TrialNOT YET RECRUITING
Jan 2026Entecavir With or Without Pegylated Interferon α-2b in Children Aged 3-6 Years With Immune-Tolerant Chronic Hepatitis B

Qing-Lei Zeng — PHASE4

TrialNOT YET RECRUITING
Dec 2025Ketamine-assisted Integrative Treatment for Veterans With Chronic Low Back Pain and Comorbid Depression

VA Office of Research and Development — PHASE2

TrialRECRUITING

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Treatments

2 available

Dyural 80-Lm

METHYLPREDNISOLONE ACETATE, LIDOCAINE HYDROCHLORIDE, BUPIVACAINE HYDROCHLORIDE, POVIDINE IODINE, ISOPROPYL ALCOHOL· Advanced Rx Pharmacy of Tennessee, LLC■ Boxed Warning

To tide the patient over a critical period of the disease in ulcerative colitis

HUMIRA

adalimumab· AbbVie, Inc.■ Boxed Warning

Treatment of moderately to severely active ulcerative colitis in adults and pediatric patients 5 years of age and older

Clinical Trials

16 recruitingView all trials with filters →
Phase 31 trial
Extension Trial on Efficacy / Safety of L-CsA + SoC in Treating BOS in Post Single or Double Lung Transplant (BOSTON-3)
Phase 3
Active
PI: Paola R Castellani, MD (Zambon SpA, Chief Medical Officer) · Sites: Phoenix, Arizona; Los Angeles, California +35 more · Age: 1899 yrs
Phase 26 trials
A Rollover Study to Provide Continued Treatment for Participants Previously Enrolled in Studies of Itacitinib
Phase 2
Active
PI: Lance Leopold, MD (Incyte Corporation) · Sites: Duarte, California; Aurora, Colorado +19 more · Age: 1899 yrs
BElumosudil for Bronchiolitis Obliterans Prevention/Therapy (BEBOP)
Phase 2
Actively Recruiting
PI: Corey Cutler, MD, MPH (Dana-Farber Cancer Institute) · Sites: Boston, Massachusetts; Boston, Massachusetts +3 more · Age: 1899 yrs
Ruxolitinib for Early Lung Dysfunction After Hematopoietic Stem Cell Transplant
Phase 2
Active
PI: Kasiani Myers, MD (Children's Hospital Medical Center, Cincinnati) · Sites: Minneapolis, Minnesota; Cincinnati, Ohio · Age: 560 yrs
Nintedanib in Patients With Bronchiolitis Obliterans Syndrome Following Hematopoietic Stem Cell Transplantation
Phase 2
Actively Recruiting
PI: Katrin Hostettler Haack, PD Dr. med (Clinic of Respiratory Medicine, University Hospita) · Sites: Riyadh; Basel +1 more · Age: 1899 yrs
LAM-001 in Lung Transplant Recipients With Bronchiolitis Obliterans Syndrome.
Phase 2
Actively Recruiting
PI: Steven Hays, MD (University of California, San Francisco) · Sites: San Francisco, California · Age: 1899 yrs
Belumosudil to Block Chronic Lung Allograft Dysfunction (CLAD) in High Risk Lung Transplant Recipients
Phase 2
Actively Recruiting
PI: Scott M. Palmer, M.D., M.H.S. (Duke University Medical Center: Transplantation) · Sites: Los Angeles, California; Baltimore, Maryland +8 more · Age: 1299 yrs
N/A2 trials
Bronchial Epithelium of Children With Post-infectious Bronchiolitis Obliterans
N/A
Actively Recruiting
PI: Julie MAZENQ, PhD (APHP Marseille) · Sites: Marseille · Age: 06 yrs
Pulsed Radiofrequency of Shoulder Individual Nerves Versus Brachial Plexus in Management of Chronic Post Mastectomy Shoulder Pain
N/A
Actively Recruiting
· Sites: Cairo · Age: 1865 yrs
Other5 trials
TRANSPIRE: Lung Injury in a Longitudinal Cohort of Pediatric HSCT Patients
Actively Recruiting
PI: Stella Davies, MBBS, PhD, MRCP (Children's Hospital Medical Center, Cincinnati) · Sites: San Francisco, California; Aurora, Colorado +7 more · Age: 024 yrs
Evaluating Clonogenic Epithelial Cell Populations in Patients With Bronchiolitis Obliterans Syndrome
Actively Recruiting
PI: Ajay Sheshadri (M.D. Anderson Cancer Center) · Sites: Houston, Texas
TRAnscriptional Profile of Peripheral Blood Cells in Patient With Chronic Kidney and Lung Rejection: Correlation With Response to Extracorporeal Photo-aphereSiS
Active
· Sites: Pavia, Pavia · Age: 1899 yrs
Signature of the Host Response to a Respiratory Viral Infection, in the Prediction of Bronchiolitis Obliterans
Actively Recruiting
· Sites: Paris, Île-de-France Region · Age: 1899 yrs
The Longitudinal Impact of Respiratory Viruses on Bronchiolitis Obliterans Syndrome After Allogeneic Hematopoietic Cell Transplantation (The RV-BOS Study)
Actively Recruiting
PI: Guang-Shing Cheng, MD (Fred Hutch/University of Washington Cancer Consort) · Sites: Palo Alto, California; Ann Arbor, Michigan +2 more · Age: 899 yrs

Specialists

Showing 25 of 75View all specialists →
MP
Márcio VF Donadio, PhD
Specialist
PI on 1 active trial
HM
He Huang, MD
Hanzhou, Zhejiang
Specialist

Rare Disease Specialist

PI on 11 active trials
GM
Guang-Shing Cheng, MD
SEATTLE, WA
Specialist
PI on 1 active trial1 Bronchiolitis obliterans publication
MS
Mikhail Samsonov
Specialist
PI on 17 active trials
CM
Corey Cutler, MD, MPH
PARK CITY, UT
Specialist
PI on 3 active trials
RM
Robert J Kreitman, M.D.
OLNEY, MD
Specialist
PI on 12 active trials
OP
Olivier Brugière, MD, PhD
Specialist
PI on 1 active trial
CM
Christopher G Kanakry, M.D.
BALTIMORE, MD
Specialist
PI on 4 active trials
SM
Stella Davies, MBBS, PhD, MRCP
CINCINNATI, OH
Specialist
PI on 2 active trials
KM
Kevin C Conlon, M.D.
IRVINE, CA
Specialist
PI on 8 active trials
MM
Muna Qayed, MD
ATLANTA, GA
Specialist
PI on 2 active trials
JH
Jiong Hu
SAN FRANCISCO, CA
Specialist
PI on 3 active trials
NP
Noha O. Mansour, Ph.D.
Specialist
PI on 1 active trial
JM
Jane Apperley, MD
Specialist
PI on 1 active trial
SM
Stephen G O'Brien, MD
Specialist
PI on 1 active trial
JM
Justin Wahlstrom, MD
SAN FRANCISCO, CA
Specialist
PI on 1 active trial
RM
Richard E Clark, MD
Specialist
PI on 1 active trial
RD
Robert H. Hyland, DPhil
Specialist
PI on 2 active trials
DD
Dirk Rades, Prof. Dr.
Specialist
PI on 2 active trials

Treatment Centers

8 centers
⚗️ Trial Site

Children's Hospital Colorado

📍 Aurora, Colorado

👤 Zachary Grinspan, MD

⚗️ Trial Site

Boston Children's Hospital

📍 Boston, Massachusetts

⚗️ Trial Site

Children's National Medical Center

📍 Washington D.C., District of Columbia

👤 Richard Neibeger, MD

⚗️ Trial Site

Ann & Robert H. Lurie Children's Hospital of Chicago

📍 Chicago, Illinois

⚗️ Trial Site

Northwestern University

📍 Chicago, Illinois

👤 Ann (Annie) W Silk

🔬 UDN

Harvard/MGH UDN Clinical Site

Massachusetts General Hospital

📍 Boston, MA

🔬 UDN

Baylor College of Medicine UDN Clinical Site

Baylor College of Medicine

📍 Houston, TX

🏥 NORD

Stanford Medicine Rare Disease Center

Stanford Medicine

📍 Stanford, CA

Financial Resources

3 resources

Lialda

Takeda

Ulcerative Colitis

Unverified — confirm before calling
copay card
Copay CardPatient Assistance
Accepting applications

Mesalamine

Takeda

Ulcerative Colitis

Unverified — confirm before calling
copay card
Copay CardPatient Assistance
Accepting applications

Mesalamine Rectal

AbbVie

Ulcerative Colitis

Unverified — confirm before calling
copay card
Copay CardPatient Assistance
Accepting applications

Travel Grants

No travel grants are currently matched to Bronchiolitis obliterans.

Search all travel grants →NORD Financial Assistance ↗

Community

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Latest news about Bronchiolitis obliterans

Disease timeline:

New recruiting trial: Freedom-1 Study for Chronic Knee Pain

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: Ibrutinib for the Prevention of Chronic Graft-Versus-Host Disease in Patients Undergoing Donor Stem Cell Transplant

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: Predictive Value of Carotid Ultrasonography for Intradialytic Hypotension

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: Comparison of the Effectiveness of Different Exercise Types in Individuals with Chronic Neck Pain

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: MENTOR Wellness Program

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: The Effects of Muscle Vibration on the Development of Spasticity and Neuroplasticity in a Post-stroke Population

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: Balloon Sinuplasty Efficiency in Maxillary Rhinosinusitis.

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: A Combined Exercise Programme Involving Strengthening, Flexibility and Aerobic Exercise for Lower Back Pain

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: TRANSPIRE: Lung Injury in a Longitudinal Cohort of Pediatric HSCT Patients

A new clinical trial is recruiting patients for Bronchiolitis obliterans

New recruiting trial: Belumosudil to Block Chronic Lung Allograft Dysfunction (CLAD) in High Risk Lung Transplant Recipients

A new clinical trial is recruiting patients for Bronchiolitis obliterans

Caregiver Resources

NORD Caregiver Resources

Support, advocacy, and financial assistance for caregivers of rare disease patients.

Mental Health Support

Rare disease caregiving can be isolating. Connect with counseling and peer support.

Family & Caregiver Grants

Financial assistance programs specifically for caregivers of rare disease patients.

Social Security Disability

Learn how rare disease patients may qualify for SSDI/SSI benefits.

Questions for your doctor

Bring these to your next appointment

  • Q1.What is the likely cause of my bronchiolitis obliterans, and does that affect my treatment options?,How quickly is my lung function declining, and how often should I have pulmonary function tests?,What medications or therapies do you recommend, and what are their side effects?,Am I a candidate for pulmonary rehabilitation, and how can it help me?,At what point should we consider lung transplantation, and what does that process involve?,Are there any clinical trials or new treatments I should know about?,What can I do in my daily life to protect my lungs and slow the disease?

Common questions about Bronchiolitis obliterans

What is Bronchiolitis obliterans?

Bronchiolitis obliterans (also called obliterative bronchiolitis or constrictive bronchiolitis) is a rare and serious lung disease that affects the smallest airways in the lungs, called bronchioles. In this condition, these tiny airways become damaged and inflamed, leading to scarring and narrowing that blocks airflow. This makes it progressively harder to breathe. The disease is sometimes referred to as 'popcorn lung' because it gained public attention after cases were linked to workers inhaling diacetyl, a chemical used in microwave popcorn flavoring. The most common symptoms include a pers

How is Bronchiolitis obliterans inherited?

Bronchiolitis obliterans follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.

Are there clinical trials for Bronchiolitis obliterans?

Yes — 16 recruiting clinical trials are currently listed for Bronchiolitis obliterans on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.

Which specialists treat Bronchiolitis obliterans?

25 specialists and care centers treating Bronchiolitis obliterans are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.

What treatment and support options exist for Bronchiolitis obliterans?

3 patient support programs are currently tracked on UniteRare for Bronchiolitis obliterans. See the treatments and support programs sections for copay assistance, eligibility, and contact details.