Flock worker's lung
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:
Synonyms and keywords: Synonym 1; Synonym 2; Synonym 3
Overview
Flock Worker's Lung.
Historical Perspective
- Since 1975, published case reports have raised suspicion of a respiratory hazard associated with various synthetic fibers, including polyester, nylon, and acrylic dust.
- Early reports in 1974 and 1981 of workplace evaluations by National Institute of Occupational Safety and Health (NIOSH) investigators attributed respiratory symptoms among workers to irritant properties of nonrespirable flock fibers on the upper airways but did not pursue the possibility of lung disease associated with flock work [1]
- During 1990 and 1991, five workers from a nylon flock processing plant in Ontario presented with cough and dyspnea.[2]
- In 1995 and 1996, two workers from a similar nylon flock processing plant in Rhode Island presented separately to the same physician with cough and dyspnea
- The initial working diagnosis for the lung disease in these two workers was work-related hypersensitivity pneumonitis. With additional case finding investigation at the Rhode Island location, a total of eight cases among the approximately 150 workers at the plant were identified by January 1998 based upon a screening questionnaire (symptoms of cough and dyspnea), pulmonary function abnormalities (restrictive pattern with reduced diffusing capacity), radiographic findings and/or histological findings on tissue obtained by open lung or transbronchial lung biopsy .Based upon the aggregate histopathological results from biopsied cases, the disease process was not thought to be hypersensitivity pneumonitis.[2]
- "flock worker's lung" formally came to known in 1998, when researchers from NIOSH published the results of an epidemiological investigation of outbreaks in Ontario and Rhode Island.
- Previously, interstitial lung disease in flock workers was incorrectly attributed to mycotoxins present in contaminated adhesive.[1]
Classification
- [Disease name] may be classified according to [classification method] into [number] subtypes/groups:
- [group1]
- [group2]
- [group3]
- Other variants of [disease name] include [disease subtype 1], [disease subtype 2], and [disease subtype 3].
Pathophysiology
- Flock consists of short fibers that are cut from long filaments and glued to backing material such as cloth to provide a fuzzy, carpet-like surface texture. They are usually prepared from synthetic materials such as nylon, rayon, or polypropylene. The cutting process results in formation of airborne particles or fibers in the respirable range. Inhalation of flock dust causes an interstitial lung disease.[3]
- Preliminary toxicologic studies suggest that ultrafine respirable fragments of nylon cause an acute inflammatory lung injury in rats after a single intratracheal instillation. However, flock finishing agents or other components of the particulate matter present in the air of flock processing plants cannot yet be ruled out.
- The interstitial pneumonitis we have studied among nylon flock processing workers has a histopathological pattern— bronchiolar and peribronchiolar lymphocytic inflammation and lymphoid hyperplasia—which suggests an inflammatory and possibly immunologic response to a respirable toxic agent [4]
- In one study microscopic examination of polypropylene fibre-exposed lungs revealed a dose-dependent increase in cellularity (especially macrophage infiltration), but no fibrosis. In another study , the researchers found high serum IL-8 and TNF-α levels in the polypropylene flocking workers. Furthermore, these levels showed a negative correlation with DL,CO. These results suggest that IL-8 and TNF-α may act as key mediators for inflammatory lung injury in the pathogenesis of polypropylene flocking worker's lung.[5]
- The pathogenesis of [disease name] is characterized by [feature1], [feature2], and [feature3].
- The [gene name] gene/Mutation in [gene name] has been associated with the development of [disease name], involving the [molecular pathway] pathway.
- On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
- On microscopic histopathological analysis, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
Causes
- [Disease name] may be caused by either [cause1], [cause2], or [cause3].
- [Disease name] is caused by a mutation in the [gene1], [gene2], or [gene3] gene[s].
- There are no established causes for [disease name].
Differentiating [disease name] from other Diseases
- [Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as:
- [Differential dx1]
- [Differential dx2]
- [Differential dx3]
Epidemiology and Demographics
- The prevalence of [disease name] is approximately [number or range] per 100,000 individuals worldwide.
- In [year], the incidence of [disease name] was estimated to be [number or range] cases per 100,000 individuals in [location].
Age
- Patients of all age groups may develop [disease name].
- [Disease name] is more commonly observed among patients aged [age range] years old.
- [Disease name] is more commonly observed among [elderly patients/young patients/children].
Gender
- [Disease name] affects men and women equally.
- [Gender 1] are more commonly affected with [disease name] than [gender 2].
- The [gender 1] to [Gender 2] ratio is approximately [number > 1] to 1.
Race
- There is no racial predilection for [disease name].
- [Disease name] usually affects individuals of the [race 1] race.
- [Race 2] individuals are less likely to develop [disease name].
Risk Factors
- Common risk factors in the development of [disease name] are [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
Natural History, Complications and Prognosis
- The majority of patients with [disease name] remain asymptomatic for [duration/years].
- Early clinical features include [manifestation 1], [manifestation 2], and [manifestation 3].
- If left untreated, [#%] of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
- Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
- Prognosis is generally [excellent/good/poor], and the [1/5/10year mortality/survival rate] of patients with [disease name] is approximately [#%].
Diagnosis
Diagnostic Criteria
- The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met:
- [criterion 1]
- [criterion 2]
- [criterion 3]
- [criterion 4]
Symptoms
- [Disease name] is usually asymptomatic.
- Symptoms of [disease name] may include the following:
- [symptom 1]
- [symptom 2]
- [symptom 3]
- [symptom 4]
- [symptom 5]
- [symptom 6]
Physical Examination
- Patients with [disease name] usually appear [general appearance].
- Physical examination may be remarkable for:
- [finding 1]
- [finding 2]
- [finding 3]
- [finding 4]
- [finding 5]
- [finding 6]
Laboratory Findings
- There are no specific laboratory findings associated with [disease name].
- A [positive/negative] [test name] is diagnostic of [disease name].
- An [elevated/reduced] concentration of [serum/blood/urinary/CSF/other] [lab test] is diagnostic of [disease name].
- Other laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
Imaging Findings
- There are no [imaging study] findings associated with [disease name].
- [Imaging study 1] is the imaging modality of choice for [disease name].
- On [imaging study 1], [disease name] is characterized by [finding 1], [finding 2], and [finding 3].
- [Imaging study 2] may demonstrate [finding 1], [finding 2], and [finding 3].
Other Diagnostic Studies
- [Disease name] may also be diagnosed using [diagnostic study name].
- Findings on [diagnostic study name] include [finding 1], [finding 2], and [finding 3].
Treatment
Medical Therapy
- There is no treatment for [disease name]; the mainstay of therapy is supportive care.
- The mainstay of therapy for [disease name] is [medical therapy 1] and [medical therapy 2].
- [Medical therapy 1] acts by [mechanism of action 1].
- Response to [medical therapy 1] can be monitored with [test/physical finding/imaging] every [frequency/duration].
Surgery
- Surgery is the mainstay of therapy for [disease name].
- [Surgical procedure] in conjunction with [chemotherapy/radiation] is the most common approach to the treatment of [disease name].
- [Surgical procedure] can only be performed for patients with [disease stage] [disease name].
Prevention
- There are no primary preventive measures available for [disease name].
- Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
- Once diagnosed and successfully treated, patients with [disease name] are followed-up every [duration]. Follow-up testing includes [test 1], [test 2], and [test 3].
References
- ↑ 1.0 1.1 Kreiss K (June 2013). "Occupational lung disease: from case reports to prevention". Chest. 143 (6): 1529–1531. doi:10.1378/chest.12-3001. PMC 3673658. PMID 23732577.
- ↑ 2.0 2.1 Eschenbacher WL, Kreiss K, Lougheed MD, Pransky GS, Day B, Castellan RM (June 1999). "Nylon flock-associated interstitial lung disease". Am. J. Respir. Crit. Care Med. 159 (6): 2003–8. doi:10.1164/ajrccm.159.6.9808002. PMID 10351952.
- ↑ "CDC - NIOSH Program Portfolio : Respiratory Diseases : Risks".
- ↑ Eschenbacher, William L.; Kreiss, Kathleen; Lougheed, M. Diane; Pransky, Glenn S.; Day, Brian; Castellan, Robert M. (1999). "Nylon Flock–Associated Interstitial Lung Disease". American Journal of Respiratory and Critical Care Medicine. 159 (6): 2003–2008. doi:10.1164/ajrccm.159.6.9808002. ISSN 1073-449X.
- ↑ Atis, S. (2005). "The respiratory effects of occupational polypropylene flock exposure". European Respiratory Journal. 25 (1): 110–117. doi:10.1183/09031936.04.00138403. ISSN 0903-1936.