Following its relatively recent birth in the 1700s from the pioneering work of Dr. Bernardino Ramazzini, occupational medicine has grown to encompass an array of respiratory conditions. One such condition is byssinosis, a collection of respiratory symptoms elicited by exposure to raw non-synthetic textiles during their manufacturing process. Over the years, byssinosis has been referred to as cotton worker's lung, brown lung disease, Monday fever, and mill fever.
In 1978, the Occupational Safety and Health Administration (OSHA) published a mandatory standard regarding exposure to cotton dust in the workplace which both improved both the detection and prevention of byssinosis.
Byssinosis is more common in people who work in the textile industry where cotton fabrics are made. In the United States, the disease is most common in Georgia, North and South Carolina, and Maryland.,,
Classically, exposure to cotton dust during the spinning and manufacturing process causes byssinosis. However, exposure to jute, flax, and hemp fibers have been implicated in its development. Recent studies identified that endotoxin released from the cell wall of bacteria within textile fibers contributes to byssinosis symptoms.
Data published by the Center for Disease Control (CDC) confirms a significant decline in the number of reported deaths from byssinosis between 1979 to 2010; however, comprehensive epidemiological data are lacking. Based on some older data, the quoted prevalence of byssinosis in the United Kingdom about 4%.
Outside of North America, byssinosis is not rare at all. In countries where cotton industries flourish, such as India, Pakistan, Nepal, Sri Lanka, and Bangladesh, byssinosis is common. In addition to the cotton industry, exposure to jute, hemp, and flex also cause byssinosis. The general population in these countries also smokes heavily which tends to exacerbate the symptoms. Despite modernization and introducing better working environments, byssinosis still is common in many parts of Pakistan, India, Indonesia, Ethiopia, Turkey, and Sudan.,
Not only is cotton dust implicated in the pathogenesis but also the endotoxin level in the work environment. This endotoxin is a lipopolysaccharide found in the outer membrane of gram-negative bacteria which reside within the cotton dust. Exposure has been implicated as the key mediator of respiratory disease among these workers with studies showing a decline in FEV1 with endotoxin exposure. However, this is not uniform, and there seems to be a variable response - with an even greater decline in FEV1 in those with polymorphisms in the tumor necrosis factor (TNF) gene.,,
The beginning steps in yarn preparation produce the most dust. Therefore, the closer to the beginning of the process the person is, the higher the level of dust exposure and the greater risk of experiencing a pulmonary reaction or response.
Symptoms manifest as frequent coughing, chest tightness, dyspnea, and at times, wheezing, particularly within a few hours of exposure (or reexposure) to the workplace. Hence, patients usually report symptoms towards the beginning of their work week and thus the term Monday fever. This is in contrast to patients with occupational asthma who experience symptoms towards the end of their work week. Once exposure and lung irritation becomes persistent, patients will no longer have cyclical symptoms and progress to the chronic byssinosis state.
In conjunction with the above symptoms, cough with sputum production may also manifest, which can lead to a misdiagnosis of chronic obstructive pulmonary disease (COPD) or bronchitis.
There are no known diagnostic tests for byssinosis. However, acute exposure to cotton dust can result in a serological increase in leukocyte count. The diagnosis is often difficult because the condition can mimic asthma and many other pneumoconioses. Besides the physical exam, which is nonspecific, a chest x-ray is required to rule out other pathologies. The biggest clue to the disease is that the patient will usually complain that the symptoms get worse when he or she comes to work on Monday (hence the name Monday disease) and gets better when off work.
Pulmonary function testing (PFT) can support suspected byssinosis by revealing a decline in forced expiratory volume over 1 second (FEV1) below 80% of their predicted values or a greater than 5% decline in their intrashift FEV1. The normal, physiologic 20 mL to 30mL annual decline in FEV1 seems to be accelerated to a value closer to 50 mL/year in cotton workers.
A chest CT scan is usually done when the diagnosis is uncertain or when one wants to rule out other disorders.
Removing themselves from the work environment seems to be a beneficial approach for these patients. However, the available data on an annual FEV1 decline is conflicting.
After that symptomatic management with short- and long-acting, inhaled beta-agonists and perhaps corticosteroid inhalers may be necessary. Bronchodilators may be required for many months to improve symptoms. A short course of steroids does help those with severe symptoms.
The majority of people recover uneventfully with treatment, but at the same time, one needs to avoid exposure to cotton. For those individuals who are misdiagnosed or untreated, the chronic exposure to cotton can lead to lung fibrosis and impaired lung function. Most of these individuals will require oxygen and have impaired exercise function. Deaths from chronic exposure are not uncommon in Pakistan and India where textile industries still flourish, without preventive measures for workers.
Once the condition is diagnosed, the patient must be told to avoid all exposure to cotton and other fabrics. One may require a change in career to avoid further exposure to cotton.
Physical rehabilitation may benefit patients who have had long-term exposure.
Close follow up with the primary physician is needed for monitoring of lung function.
Once the diagnosis of byssinosis is made, the patient should be referred to a pulmonologist for care.
The best way to avoid byssinosis is by avoiding exposure to cotton and other related fabrics. If this is not possible, the worker should wear an appropriate mask to prevent inhalation of the particles.
Prevention lies predominantly with raw textile processor adherence to the Occupational Safety and Health Administration (OSHA) regulations. This includes enforcement of respirator mask use, dust control with extractor fans and adequate ventilation, bactericidal treatment of raw products, and continued annual employee medicals check-ups, including byssinosis symptom questionnaires, spirometry, and intra-shift spirometry.
Avoiding tobacco smoking is likely to reduce the severity of symptoms, however, robust evidence proving this is lacking.