<unk>  has many possible causes, including collagen vascular disease, transplant rejection in organ transplant patients, viral infection (adenovirus, respiratory syncytial virus, influenza, HIV, cytomegalovirus), Stevens–Johnson syndrome, Pneumocystis pneumonia, drug reaction, aspiration and complications of prematurity (bronchopulmonary dysplasia), and exposure to toxic fumes, including diacetyl, sulfur dioxide, nitrogen dioxide, ammonia, chlorine, thionyl chloride, methyl isocyanate, hydrogen fluoride, hydrogen bromide, hydrogen chloride, hydrogen sulfide, phosgene, polyamide-amine dyes, mustard gas and ozone. It can also be present in patients with IBD, systemic lupus erythematosus, juvenile idiopathic arthritis, rheumatoid arthritis, GERD, IgA nephropathy, and ataxia telangiectasia. Activated charcoal has been known to cause it when aspirated. The ingestion of large doses of papaverine in the vegetable Sauropus androgynus has caused it. Additionally, the disorder may be idiopathic (without known cause). Lung transplant<unk>  is a common complication in lung transplants because transplanted lungs are at greater risk of alloimmunization as compared to healthy lungs. The disease is often termed<unk>  syndrome <unk> S) in the setting of post lung transplantation and hematopoietic stem cell transplant (HSCT). Patients who develop<unk> S post lung transplant vary in disease latency and severity. Patients often initially have normal lung function on pulmonary function testing and have normal chest radiographs. As the disease progresses they begin to have symptoms of shortness of breath, cough, and wheezing as their lung function declines. The Journal of Heart and Lung Transplantation published updated guidelines in 2001 for grading the severity of<unk> S. The original guidelines and classification system were published in 1993 by the International Society for Heart and Lung Transplantation. Their scoring system is based on the changes in FEV1 in patients from their baseline. When patients are first diagnosed with<unk> S they have their baseline lung function established by doing pulmonary function testing at the time of diagnosis. The<unk> S scoring system is as follows:<unk> S 0: FEV1 > 90% of baseline and FEF25-75 > 75% of baseline<unk> S 0-p: FEV1 81-89% of baseline and/or FEF25-75 1 66-80% of baseline<unk> S 2: FEV1 51-65% of baseline<unk> S 3: FEV1 50% or less of baseline The scoring system shows an increased severity of the disease as the<unk> S number increases. Hematopoietic stem cell transplant<unk>  affects up to 5.5% of people who have received HSCT. One of the biggest risk factors after HSCT is the development of GVHD with a 14% risk. Other risk factors post transplant including tobacco use, age of donor, age of recipient, lower baseline FEV1/FVC ratio, non-caucasian race, peripheral and lower circulating IgG levels. Studies have, however, shown mixed results regarding these other risk factors. There has been an association shown between the increased use of peripheral stem cells and the risk of developing<unk> . Also, research has shown an increased risk for developing the disease within the first year of transplant if the person is infected with respiratory syncytial virus or parainfluenza virus within the first 100 days post transplant. Inhalants alt There are many industrial inhalants that are known to cause various types of<unk> , including<unk> . Industrial workers who have presented with<unk> : * nylon-flock workers * workers who spray prints onto textiles with polyamide-amine dyes * battery workers who are exposed to thionyl chloride fumes * workers at plants that use or manufacture flavorings such as diacetyl Diacetyl is a chemical used to produce the artificial butter flavoring in many foods such as candy and microwave popcorn and occurring naturally in wines. This first came to public attention when eight former employees of the Gilster-Mary Lee popcorn plant in Jasper, Missouri developed<unk> . Due to this event,<unk>  began to be referred to in the popular media as "popcorn lung" or "popcorn workers lung". It is also referred to as "flavorings-related lung disease". Post-infectious High-resolution CT scan of a child with post-infectious<unk>  showing glass pattern with air trapping and bronchial thickening Typically found in young children and is the most common cause at this age. Generally occurs after a viral infection of adenovirus (types 3, 7, and 21), measles (rubeola), mycoplasma, CMV, influenza, and parainfluenza. Swyer-James syndrome is a rare complication of<unk>  caused by measles or adenovirus. Post-infectious<unk>  is most common in the southern hemisphere particularly in countries such as Brazil, Argentina, Australia, Chile and New Zealand. There was a large prevalence of the disease in these areas during the 1990s and early 2000s. In one hospital in Buenos Aires, the Ricardo Gutiérrez Children's hospital, the disease accounted for 14% of their inpatient respiratory population from 1993 to 2002. As such, much of the information about post-infectious<unk>  has come from research out of South America. The most significant risk factors for the disease are infection with adenovirus and the need for ventilator support. In contrast with another cause of<unk>  in children, Steven's Johnson's syndrome, post-infectious<unk>  tends to be a chronic but non-progressive disease. The disease can have varying impact on children and their quality of life, which has been studied by lung function tests, as well as their exercise tolerance. Children with lower lung function based on their pulmonary function testing, have lower exercise tolerance, which compounds the impact of the disease on cardiovascular function as they are not able to maintain age appropriate aerobic fitness. This ultimately affects their activities of daily living (ADLs) and their quality of life going forward. Burn pits A form of constrictive<unk>  is starting to present in Iraq and Afghanistan veterans. It has been attributed to veterans being exposed to trash burn pits. Veterans present with shortness of breath and other asthma-like symptoms. The only way to diagnose this condition is by doing a lung biopsy as chest X-rays and CT scans come back as normal. The government still denies that there is any correlation between burn pits and health problems but the government has started an "Airborne Hazards and Open Burn Pit Registry" to begin tracking the health of veterans who were exposed to burn pits to see if there is a connection. E-cigarettes The American Lung Association lists flavored e-cigarettes as a risk in 2016. Health Canada has, however seen no cases as of 2019. Public Health England writes that the association has come about as "some flavourings used in e-liquids to provide a buttery flavour contain the chemical diacetyl... however, diacetyl is banned as an ingredient from e-cigarettes and e-liquids in the UK."
Bronchiolitis obliterans
Asthma
Diffuse panbronchiolitis
Emphysema
Mineral dust airway disease
Eosinophilic bronchitis
Plastic bronchitis
Pulmonary hyalinizing granuloma