| Farmer's lung | |
|---|---|
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| Hay shed | |
| Specialty | Respirology |
Farmer's lung (not to be confused with silo-filler's disease) is a hypersensitivity pneumonitis induced by the inhalation of biologic dusts coming from hay dust or mold spores or any other agricultural products. [1] It results in a type III hypersensitivity inflammatory response and can progress to become a chronic condition which is considered potentially dangerous. [2]
These symptoms develop between four and eight hours after exposure to the antigens. In acute attacks, the symptoms mimic pneumonia or flu. In chronic attacks, there is a possibility of the victim going into shock and dying from the attack. [5]
Permanent lung damage can arise due to one's inability to recognize the cause of symptoms. [5] Farmer's lung occurs because repeated exposure to antigens, found in the mold spores of hay, crops, and animal feed, triggers an allergic reaction within the farmer's immune system. [5] The defense mechanisms of the body present as cold and flu-like symptoms that occur in individuals who experience either acute or chronic reactions. [5]
The mold spores are inhaled and provoke the creation of IgE antibodies that circulate in the bloodstream, these types of immune response are most often initiated by exposure to thermophilic actinomycetes (most commonly Saccharopolyspora rectivirgula ), which generate IgG-type antibodies. Following a subsequent exposure, IgG antibodies combined with the inhaled allergen to form immune complexes in the walls of the alveoli in the lungs. [6] This causes fluid, protein, and cells to accumulate in the alveolar wall which slows blood-gas interchange and compromises the function of the lung. After multiple exposures, it takes less and less of the antigens to set off the reaction in the lung. [7]
Farmer's lung disease (FLD) is permanent and cannot be reversed, therefore in order to prevent the onset of further stages, farmers should inform their doctor of their occupation and if they have mold in their work environment. [3] Prevention of this respiratory illness can be facilitated through the ventilation of work areas, drying of materials, and the use of a mask when working in confined areas with moldy hay or crops. [5]
[4] Diagnoses of Farmer's lung is difficult due to its similarity to cold and flu-like symptoms. [8] Doctors diagnose patients with Farmer's lung under the following conditions:
Examination procedures may include:
• taking a blood test [3] [9]
• taking a chest x-ray [3] [9]
• administering a breathing capacity test [3] [4]
• administering an inhalation challenge [3] [4]
• examining lung tissue [3] [9]
• performing an immunological investigation [3] [4]
• performing a lung function test [3] [9]
• reviewing the clinical history [3] [4]
Depending on the severity of the symptoms, FLD can last from one to two weeks, or it can last for the rest of one's life. Acute FLD has the ability to be treated because hypersensitivity to the antigens has not yet developed. The main treatment options are: rest and reducing the exposure to the antigens through masks and increased airflow in confined spaces where the antigens are present. [5] Any exposure to the antigens once hypersensitivity has occurred can set off another chronic reaction. [5] For chronic FLD, there are no true treatments because the patient has developed hypersensitivity meaning that their condition will last the rest of their life.
The growth of mold spores occurs when hay is not dried properly. [10] The growth of these mold spores accumulates over time and will infect the host upon release from the source. [11] When in the air, the farmer may inhale the particles and induce an allergic reaction. [11] The hay at risk for increased volumes of spores is found at the bottom of the pile. [11] The presence of Farmer's Lung Disease peaks during late winter and early spring and is mostly seen after the harvest season when symptoms have set in. [12] This disease is most prevalent in damp climates. [12]
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.
A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.
Hypersensitivity refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune system and these reactions may be damaging and uncomfortable. This is an immunologic term and is not to be confused with the psychiatric term of being hypersensitive which implies to an individual who may be overly sensitive to physical and/or emotional stimuli. Although there is a relation between the two - studies have shown that those individuals that have ADHD are more likely to have hypersensitivity reactions such as allergies, asthma, eczema than those who do not have ADHD.
Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. It is marked by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs. It is a type of pneumoconiosis. Silicosis is characterized by shortness of breath, cough, fever, and cyanosis. It may often be misdiagnosed as pulmonary edema, pneumonia, or tuberculosis.
Goodpasture syndrome (GPS), also known as anti–glomerular basement membrane disease, is a rare autoimmune disease in which antibodies attack the basement membrane in lungs and kidneys, leading to bleeding from the lungs, glomerulonephritis, and kidney failure. It is thought to attack the alpha-3 subunit of type IV collagen, which has therefore been referred to as Goodpasture's antigen. Goodpasture syndrome may quickly result in permanent lung and kidney damage, often leading to death. It is treated with medications that suppress the immune system such as corticosteroids and cyclophosphamide, and with plasmapheresis, in which the antibodies are removed from the blood.
Type I hypersensitivity is an allergic reaction provoked by re-exposure to a specific type of antigen referred to as an allergen. Type I is distinct from type II, type III and type IV hypersensitivities.
Chemical pneumonitis is inflammation of the lung caused by aspirating or inhaling irritants. It is sometimes called a "chemical pneumonia", though it is not infectious. There are two general types of chemical pneumonitis: acute and chronic.
Rhinorrhea or rhinorrhoea is the free discharge of a thin nasal mucus fluid. The condition, commonly known as a runny nose, occurs relatively frequently. Rhinorrhea is a common symptom of allergies or certain viral infections, such as the common cold. It can be a side effect of crying, exposure to cold temperatures, cocaine abuse, or withdrawal, such as from opioids like methadone. Treatment for rhinorrhea is not usually necessary, but there are a number of medical treatments and preventive techniques available.
Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis (EAA) is a rare immune system disorder that affects the lungs. It is an inflammation of the airspaces (alveoli) and small airways (bronchioles) within the lung, caused by hypersensitivity to inhaled organic dusts and molds. People affected by this type of lung inflammation (pneumonitis) are commonly exposed to the dust and mold by their occupation or hobbies.
Pneumonitis describes general inflammation of lung tissue. Possible causative agents include radiation therapy of the chest, exposure to medications used during chemo-therapy, the inhalation of debris, aspiration, herbicides or fluorocarbons and some systemic diseases. If unresolved, continued inflammation can result in irreparable damage such as pulmonary fibrosis.
Eosinophilic pneumonia is a disease in which an eosinophil, a type of white blood cell, accumulates in the lungs. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kinds of eosinophilic pneumonia exist and can occur in any age group. The most common symptoms include cough, fever, difficulty breathing, and sweating at night. Eosinophilic pneumonia is diagnosed by a combination of characteristic symptoms, findings on a physical examination by a health provider, and the results of blood tests and X-rays. Prognosis is excellent once most eosinophilic pneumonia is recognized and treatment with corticosteroids is begun.
Acute severe asthma, also known as status asthmaticus, is an acute exacerbation of asthma that does not respond to standard treatments of bronchodilators (inhalers) and corticosteroids. Asthma is caused by multiple genes, some having protective effect, with each gene having its own tendency to be influenced by the environment although a genetic link leading to acute severe asthma is still unknown. Symptoms include chest tightness, rapidly progressive dyspnea(shortness of breath), dry cough, use of accessory respiratory muscles, fast and/or labored breathing, and extreme wheezing. It is a life-threatening episode of airway obstruction and is considered a medical emergency. Complications include cardiac and/or respiratory arrest. The increasing prevalence of atopy and asthma remains unexplained but may be due to infection with respiratory viruses.
Occupational lung diseases are work-related, lung conditions that have been caused or made worse by the materials a person is exposed to within the workplace. It includes a broad group of diseases, including occupational asthma, industrial bronchitis, chronic obstructive pulmonary disease (COPD), bronchiolitis obliterans, inhalation injury, interstitial lung diseases, infections, lung cancer and mesothelioma. These diseases can be caused directly or due to immunological response to an exposure to a variety of dusts, chemicals, proteins or organisms.
Allergic bronchopulmonary aspergillosis (ABPA) is a condition characterised by an exaggerated response of the immune system to the fungus Aspergillus. It occurs most often in people with asthma or cystic fibrosis. Aspergillus spores are ubiquitous in soil and are commonly found in the sputum of healthy individuals. A. fumigatus is responsible for a spectrum of lung diseases known as aspergilloses.
Recurrent airway obstruction, also known as broken wind, heaves, wind-broke horse, or sometimes by the term usually reserved for humans, chronic obstructive pulmonary disease or disorder (COPD) – it is a respiratory disease or chronic condition of horses involving an allergic bronchitis characterised by wheezing, coughing and laboured breathing.
Bird fancier's lung (BFL) is a type of hypersensitivity pneumonitis. It can cause shortness of breath, fever, dry cough, chest pain, anorexia and weight loss, fatigue, and progressive pulmonary fibrosis. It is triggered by exposure to avian proteins present in the dry dust of droppings or feathers of a variety of birds. The lungs become inflamed, with granuloma formation. It mostly affects people who work with birds or own many birds.
A drug allergy is an allergy to a drug, most commonly a medication, and is a form of adverse drug reaction. Medical attention should be sought immediately if an allergic reaction is suspected.
The use of podiatry drills, in the absence of engineering controls and personal protective equipment, is an occupational hazard to the healthcare provider. Nail dust collected during foot care procedures performed in office settings has been found to contain keratin, keratin hydrolysates, microbial debris, and viable fungal elements, including dermatophytes and saprotrophs. Exposure to nail dust and the associated risk will vary with the policies and practices in place, the type of podiatry drill used, therapy technique, frequency of procedures, personal protective equipment utilized and the use of ventilation systems.
Lycoperdonosis is a respiratory disease caused by the inhalation of large amounts of spores from mature puffballs. It is classified as a hypersensitivity pneumonitis —an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled natural dusts. It is one of several types of hypersensitivity pneumonitis caused by different agents that have similar clinical features. Typical progression of the disease includes symptoms of a cold hours after spore inhalation, followed by nausea, rapid pulse, crepitant rales, and dyspnea. Chest radiographs reveal the presence of lung nodules. The early symptoms presented in combination with pulmonary abnormalities apparent on chest radiographs may lead to misdiagnosis of the disease as tuberculosis, histiocytosis, or pneumonia caused by Pneumocystis carinii. Lycoperdonosis is generally treated with corticosteroids, which decrease the inflammatory response; these are sometimes given in conjunction with antimicrobials.
Organic dust toxic syndrome is a potentially severe flu-like syndrome originally described in farmers, mushroom workers, bird breeders and other persons occupationally exposed to dusty conditions.