Sarcoidosis is a disease that invovles many parts of the body, most often the lungs and lymph nodes. It affects the terminal parts of the lungs which are called the pulmonary alveoli and the tissue between them. The alveoli have a circular shape and are arranged next to one another, in between which is lung tissue and blood vessels. This structure is microscopic. The alveoli ensure the exchange of oxygen and carbon dioxide between the blood and air. In the end stages of the disease, the abnormal growth of fibrous lung tissue leads to the destruction of the alveoli and interferes with the exchange of gases. Sarcoidosis may also affect the skin, joints, muscles, heart, liver, kidneys and other organs.
Cause of sarcoidosis
Sarcoidosis is a chronic disease that develops over many years. Its progress is variable and differs among individuals and even differs depending on the stage of the disease. The cause of sarcoidosis is still not known. It is assumed that the triggering factor is most likely a viral infection that strongly reacts with the immune system and results in the damage of various organs and tissues. It is also assumed that certain individuals are genetically predisposed to this disease. Sarcoidosis affects young to middle-aged adults between the ages of twenty and forty. The prognosis is often favorable, in 2/3 of the cases the disease goes away on its own. The remaining 1/3 of cases progress into chronicity and worsen over time.
Types of sarcoidosis and its symptoms
There is a very wide spectrum of symptoms for sarcoidosis which can make it difficult to diagnose. In certain phases of sarcoidosis, the symptoms are similar to other diseases such as influenza and even tuberculosis. Sarcoidosis exist in two forms: pulmonary, which is most common (90%) and extrapulmonary.
The pulmonary form of sarcoidosis manifests as enlarged lymph nodes surrounding the lungs. These enlarged lymph nodes, which can be palpated, press on the lungs and cause the appearance of typical symptoms, like dry cough, shortness of breath and chest pain. Other symptoms include fever, fatigue, weight loss and increased sweating.
The extrapulmonary form of sarcoidosis involves the damage of many organs. It manifests as various infections of the eyes and kidneys, infections and pain of the joints and skin lesions. For example, erythema nodosum which appears as red, circular, slightly raised and painful lesion on the skin, especially on the lower leg. It can occur acutely or chronically. The acute phase accompanies the symptoms of an infectious illness, such as fever, pain and swollen joints. Sarcoidosis can also lead to high levels of calcium in the blood which can damage tissues and organs, like the kidneys. High levels of calcium are also linked to the appearance of stomache ulcers. A rare effect of high blood calcium is on the heart, where it can lead to arrhythmias.
Diagnosis and treatment of sarcoidosis
A diagnosis of sarcoidosis requires the presence clinical symptoms, a positive chest X-ray, and poor lung function, which can be discovered with the help of spirometry. Sometimes, sarcoidosis can be present without causing symptoms and its diagnosis can be accidental. The chest X-ray will show damaged lungs and lymph nodes. It is also possible to use a CT scan, which is a modern diagnostic tool that uses X-rays to form a picture. Bronchscopic techniques can be used to take a biopsy of the lung tissue and also to visualize the respiratory tubes. Treatment of sarcoidosis depends of the scale of damage and the stage of the disease. Corticoids and chemotherapeutic medications are used most often. These medications cannot cure sarcoidosis but help to alleviate its symptoms. In advanced stages, a lung transplant may be necessary.
Prognosis of sarcoidosis
Sarcoidosis is a disease with a fairly good prognosis, but it must be properly treated. African American individuals have a worse prognosis, especially in those where the symptoms last for over 6 months, in the absence of erythema nodosum and when more than three organs systems are affected. The mortality of sarcoidosis is 1-5%. The cause of death is most often respiratory insufficiency, heart damage and brain damage.