Sarcoidosis in the Elderly

　　The discovery of sarcoidosis has a history of over 100 years, but its etiology is still unknown. Possible causes include infection, chemical factors, drugs, allergic reactions, immune factors, and genetic factors. Most current research focuses on exploring infectious etiologies. Some scholars believe that the etiology of sarcoidosis is multifactorial, and the disease is an immune response caused by the interaction of multiple factors, leading to the occurrence and development of the disease. Some scholars also believe that sarcoidosis has specific pathogenic factors, and the invasion route is highly likely to be through the respiratory tract, one of the bases being that intrathoracic sarcoidosis is most common in clinical practice. In recent years, there have been reports in foreign literature that the occurrence of the disease is related to social factors and environmental factors, such as reports that the number of cases is higher among nurses and people living near hospitals, suggesting that the disease has some specific pathogenic factors. The disease can also be caused by heart transplantation surgery and bone marrow transplantation. In addition, there have been reports of experimental animals being infected with the disease, suggesting that the etiology of the disease may be related to infection. However, up to now, it has not been confirmed that the disease can be transmitted among people.

　　Elderly sarcoidosis is prone to recurrent pulmonary infections, and in the late stage, complications such as bronchiectasis, hemoptysis, pulmonary fibrosis, respiratory failure, lower limb venous thrombosis, and ocular lesions such as iridocyclitis and uveitis may occur. Heart involvement, arrhythmias, sarcoid arthritis, electrolyte imbalance, heart failure, respiratory failure, and even sudden loss of consciousness and sudden death are possible complications.

　　Sarcoidosis in the elderly has various manifestations due to the invasion of different organs by the lesions, with more than 90% of sarcoidosis involving the lungs and intrathoracic lymph nodes. More than 2/3 of patients may have no clinical symptoms, and even some may have asymptomatic bilateral hilar lymph node enlargement and interstitial infiltration. Pulmonary sarcoidosis usually starts slowly, with symptoms such as chest tightness and shortness of breath, which worsens after exercise. Cough may occur, mostly dry cough. Other common systemic symptoms include fatigue, loss of appetite, joint pain, low fever, and so on. In the late stage, due to granuloma fibrosis and cystic change or bronchiectasis, patients may have recurrent pulmonary infections with cough and sputum, hemoptysis, and even sudden loss of consciousness and sudden death due to arrhythmias, sarcoid arthritis, electrolyte imbalance, heart failure, respiratory failure, and other complications. About 20% of sarcoidosis patients may involve the eyes and skin, with uveitis, iridocyclitis, conjunctivitis, and keratoconjunctivitis being common ocular lesions. The skin is most commonly affected by nodular erythema, while chronic patients often have maculopapular rash and subcutaneous nodular skin lesions. A few cases of sarcoidosis may start acutely, with symptoms such as fever and nodular erythema on the lower limbs. Severe cases may have polyarticular arthritis, known as Lofgren's syndrome, which is more common in Europe and the Caucasus and has a good prognosis. Sarcoidosis often involves the liver, accounting for about 50%, but it is rarely damage to a single organ, so diagnosis is not very difficult. The involvement of the nervous system and myocardial sarcoidosis also occur.

　　The preventive methods for elderly sarcoidosis are as follows:

　　1. Most sarcoidosis has a good prognosis, so early treatment should be sought to prevent complications.

　　2. Pay attention to personal hygiene, protect water sources, improve the environmental hygiene, and develop good living habits.

　　3. Maintain a good mental state, stable emotions, and healthy eating habits. Eat more fruits and vegetables to enhance self-immunity in daily life.

　　4. People who must work in a heavy smoke and oil environment should protect themselves as much as possible, such as wearing masks, going out to breathe some fresh air regularly, and having a check-up once a year.

　　The specific examination items for elderly sarcoidosis are as follows:

　　1. The peripheral blood lymphocyte count in patients with active sarcoidosis may decrease.

　　2. Serum globulin and specific immunoglobulin levels may increase.

　　3. Some patients may develop hypercalciuria and hypercalcemia.

　　4. In the active stage of sarcoidosis, the serum angiotensin I converting enzyme (SACE) is often elevated. It can gradually decrease and return to normal when the condition improves, but it can increase again during recurrence. However, SACE can also increase in other granulomatous diseases, making it a non-specific diagnostic indicator.

　　5. The BALF lymphocytes in sarcoidosis patients increase, and the CD4/CD8 ratio is elevated, which is of great value for the diagnosis of sarcoidosis and the determination of disease activity.

　　6. 67Ga scan: It is a sensitive indicator reflecting the activity of sarcoidosis. During the alveolitis stage of sarcoidosis activity, the uptake of 67Ga is significantly increased. However, it can also increase in other granulomatous diseases and pneumonia patients. Due to its high cost and low specificity, it is rarely used now.

　　7. Chest X-ray: Sarcoidosis shows enlarged hilar lymph nodes in both lungs, hilar lymph node enlargement with pulmonary infiltration, interstitial infiltration, normal hilar lymph nodes, pulmonary fibrosis, and scattered nodular fibrocystic changes. CT and HRCT can accurately estimate the type, extent, and size of hilar lymph nodes in sarcoidosis, with HRCT being more sensitive to pulmonary lesions.

　　8. Pulmonary function test: Early pulmonary function may be normal, but diffuse dysfunction, ventilation dysfunction, and restrictive ventilation dysfunction may occur due to further reduction in lung volume when pulmonary fibrosis develops. Hypoxemia may occur when there is severe diffuse dysfunction and ventilation dysfunction.

　　Senile nodular disease patients should eat high-protein, high-vitamin, and high-calorie foods. Avoid eating high-fat, high-sugar, and fried foods. The diet of patients should be light and easy to digest, eat more vegetables and fruits, rationally match the diet, and pay attention to adequate nutrition.

　　Patients with stage I intrathoracic nodular disease have a spontaneous regression rate of 60% to 80% within 2 years. However, the spontaneous remission rate of stage II and III patients decreases, and that of stage III patients is only 30%, most of whom eventually lead to pulmonary fibrosis, and severe cases can cause pulmonary heart disease and respiratory failure. Generally speaking, if treatment is started after 2 years, the treatment effect is poor, so early treatment should be sought.

　　Corticosteroids are still the first choice for the treatment of nodular disease to date. In patients with disseminated nodular lesions in important organs such as eyes, central nervous system, myocardium, and lungs, or with hypersplenism, hypercalcemia, corticosteroids should be used. The relative indications for corticosteroid treatment are:

　　1. Progressive or symptomatic hilar nodular disease.

　　2. Those with obvious自觉 systemic symptoms.

　　3. Skin ulcers and lymph node lesions.

　　4. Joint, nasal, pharyngeal, and bronchial mucosal lesions. Generally, prednisone or prednisolone is used for treatment, starting with a daily dose of 30-40mg, for 4-6 weeks. Effective patients can gradually reduce the dose, and when the daily dose is 20mg, it can be used for 8-12 weeks, with a maintenance dose of 5-10mg/d, for 1 year or longer. In recent years, some people have added inhaled corticosteroids to oral corticosteroid reduction in patients with only pulmonary nodular disease, with a dose of 800-1250μg/d, to smoothly reduce the dose of oral corticosteroids, thereby consolidating the efficacy and reducing the side effects of oral corticosteroids. If corticosteroids are ineffective, small doses of azathioprine or methotrexate and other cytotoxic drugs can also be used. There are reports of using chloroquine to treat skin and mucosal nodular disease, with an initial dose of 500mg, once a day for 2 weeks, and then 250mg per day, for half a year continuously, this method still needs further verification.