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Disease Profile

Bronchiolitis obliterans organizing pneumonia

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset

All ages





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

BOOP; Constrictive bronchiolitis; Organizing pneumonia


Lung Diseases


Bronchiolitis obliterans organizing pneumonia (BOOP) is a lung disease that causes inflammation in the small air tubes (bronchioles) and air sacs (alveoli).[1] BOOP typically develops in individuals between 40-60 years old; however the disorder may affect individuals of any age. The signs and symptoms of BOOP vary but often include shortness of breath, a dry cough, and fever.[2] BOOP can be caused by viral infections, various drugs, and other medical conditions. If the cause is known, the condition is called secondary BOOP. In many cases, the underlying cause of BOOP is unknown. These cases are called idiopathic BOOP or cryptogenic organizing pneumonia.[1] Treatment often includes corticosteroid medications.[3]


Signs and symptoms of BOOP vary. Some individuals with BOOP may have no apparent symptoms, while others may have severe respiratory distress as in acute, rapidly-progressive BOOP.[2] The most common signs and symptoms of BOOP include shortness of breath (dyspnea), dry cough, and fever.[1] Some people with BOOP develope a flu-like illness with cough, fever, fatigue, and weight loss.[2]


BOOP may be caused by a variety of factors, including viral infections, inhalation of toxic gases, drugs, connective tissue disorders, radiation therapy, cocaine, inflammatory bowl disease, and HIV infection. In many cases, the underlying cause of BOOP is unknown. These cases are called idiopathic BOOP or cryptogenic organizing pneumonia (COP).[1]


BOOP is typically diagnosed by lung biopsy, although imaging tests and pulmonary function tests can also provide information for diagnosis.[1]


Most cases of BOOP respond well to treatment with corticosteroids. If the condition is caused by a particular drug, stopping the drug can also improve a patient's condition.

Other medications reported in the medical literature to be beneficial for individuals on a case-by-case basis include: cyclophosphamide, erythromycin in the form of azithromycin, and Mycophenolate Mofetil (CellCept). More research is needed to determine the long-term safety and effectiveness of these potential treatment options for individuals with BOOP.

In rare cases, lung transplantation may be necessary for individuals with BOOP who do not respond to standard treatment options.[2]


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Providing General Support

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • The MayoClinic.com Web site provides further information on this topic. Click on MayoClinic.com to view the information page.
    • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers.
    • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.


        1. Vasu TS, Cavallazzi R, Hirani A, Sharma D, Weibel SB, Kane GC. Respitatory Care. August 2009; 54(8):1028-32. https://www.rcjournal.com/contents/08.09/08.09.1028.pdf.
        2. Bronchiolitis Obliterans Organizing Pneumonia. NORD. 2013; https://rarediseases.org/rare-diseases/bronchiolitis-obliterans-organizing-pneumonia/.
        3. Bronchiolitis Obliterans with Organizing Pneumonia (BOOP). American Lung Association. https://www.lung.org/lung-health-and-diseases/lung-disease-lookup/boop/. Accessed 2/16/2016.

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