Silicosis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 22, 2016
StartDiseasesSilicosis

Silicosis is a progressive form of pneumoconiosis caused by inhalation of crystalline silica dust. Silica dust is a common element in the earth’s crust and can be found in everything from rock and sand to man-made products like plaster and shingles. This lung disease is found primarily in people whose occupation involves the constant breathing in of these particles such as miners and is the most common occupational lung disease found around the globe. 

Contents

Definition & Facts

Respiratory problems resulting from inhalation of dust particle have been documented since the Greek and Roman eras. With the onset of the industrial revolution, diagnoses of silicosis increased considerably. Silicosis can be classified into four distinct groups: chronic simple, accelerated, complicated, and acute. Chronic simple silicosis is the most common. It occurs from a decade or more of exposure to low levels of crystalline silica dust. Symptoms tend to start showing between ten and thirty years after the person is first exposed.

Accelerated silicosis symptoms show within five to ten years and are caused by a higher exposure to the dust. Complicated silicosis occurs when scarring develops in the lungs and most often affects patients who already have accelerated silicosis. Acute silicosis occurs anywhere from a few weeks up to five years after being exposed to high levels of respirable silica dust. People with acute silicosis can die within a year.

Patients afflicted with any type of silicosis are especially vulnerable to contracting other respiratory diseases including tuberculosis, chronic bronchitis, and lung cancer due to the body’s inability to fight off infections

Symptoms & Complaints

Initial symptoms of silicosis may take years to show even after exposure to the crystalline silica dust no longer occurs. Most people are not diagnosed until after the age of forty. The lung damage that occurs keeps the lungs from effectively supplying oxygen to the blood. Patients may experience shortness of breath, especially after any form of physical exertion, a persistent cough, and an overall sense of fatigue.

Other symptoms include a loss of appetite which results in noticeable weight loss and pains or tightness in the chest area. The skin may start to take on a bluish tone as oxygen levels are depleted in the body (cyanosis).

As the disease worsens, symptoms become more prevalent and severe in nature. Once initial symptoms set in, they can continue to get worse even after treatment is sought. Some patients find that they have extreme difficulty performing simple aerobic activities and become housebound. 

Causes

Silicosis can occur even at small levels of exposure. Jobs such as abrasive blasting, finishing drywall and using power tools to drill concrete or remove paint and rust can all send silica dust into the air. When a person breaths in crystalline silica dust, the particles can settle in the alveolar sacs and other areas of the lungs. They act as small razor blades inside the lungs that create small cuts. The lungs are rendered incapable of removing these particles and inflammation sets in.

This inflammation eventually results in the development of nodular lesions. These lesions and the buildup of fluid that sets in dramatically reduces the breathing ability of the lungs. As the nodules grow in size, the more dramatic their effect. 

Diagnosis & Tests

When making a diagnosis of silicosis, physicians will begin by discussing the patients’ medical history and the exposure of dust incurred. They will listen to the lungs for wheezing and crackling sounds. Blood tests can show whether the symptoms are being caused by other diseases. Once these other possible causes are ruled out, a chest X-ray or other imaging procedure may then be ordered to see how bad the damage to the lungs is.

The X-ray will also show whether the patient has developed nodules in the lungs. These will appear on the X-ray as small, white spots. Pulmonary function testing can show how limited the airflow has become in the patient. Some cases will require tissue biopsy; however, this is not required in most cases. Specialists may be brought in to further confirm the presence of silicosis.

Treatment & Therapy

Silicosis can cause severe lung damage so it is important to follow treatment plans carefully. Because there is no cure for silicosis, treatments are based in relieving symptoms and preventing further damage. Patients must take extremely special care in how they treat their lungs. This means staying away from further exposure to crystalline silica dust as well as stopping habits that will irritate the lung tissue such as quitting smoking.

Over-the-counter and prescribed suppressants can help to control coughing. Antibiotics may be administered to battle lung infections. Those with a severe reduction in oxygen in the blood may be required to use an oxygen mask. Bronchodilators may be prescribed to widen the airways and help with breathing.

For the worst cases, a lung transplant may be necessary. Simple changes that lead to a healthier lifestyle can also help relieve some symptoms. Regular exercise and keeping weight under control can go a long way. It is also important to get yearly flu vaccines and pneumococcal vaccines due to the complications that may arise with occurrence of these illnesses.

Once diagnosed, a patient’s life expectancy can range from a few months to several years depending on the intensity of the lung scarring. It is often suggested that patients seek out a support group to help deal with the psychological effects of the disease. 

Prevention & Prophylaxis

While silicosis is incurable, its onset is avoidable. The best way to prevent the development of silicosis is to limit exposure to crystalline silica dust. Respirators and dust masks can help keep dust out of the lungs. Dry air filtering and water spraying can also be used to keep the dust from lingering in the air.

People should wash hands thoroughly before eating after working in dusty areas. They can keep from spreading contamination by showering and changing clothes before leaving the worksite. For those who do experience repeated exposure, yearly screenings of the lungs and overall health is vital for early detection.