Rosh Internal Medicine Boost Practice Exam

In the diagnosis of sarcoidosis, which electrolyte abnormality would be significant?

1. Bicarbonate

2. Calcium

3. Potassium

4. Sodium

The correct answer is: Calcium

In the diagnosis of sarcoidosis, the significant electrolyte abnormality is an alteration in calcium levels, particularly hypercalcemia. Sarcoidosis is a granulomatous disease that can cause increased production of calcitriol (1,25-dihydroxyvitamin D) by activated macrophages within granulomas, leading to increased intestinal absorption of calcium and reabsorption from the bones. This can result in elevated serum calcium levels, which may occur in a significant number of patients with sarcoidosis. Monitoring calcium levels can help assess the disease's activity and potential complications. Other electrolyte abnormalities, while they can occur in various conditions, are not specifically linked to sarcoidosis. For example, bicarbonate may fluctuate due to various metabolic processes but is not a defining feature of sarcoidosis. Similarly, potassium and sodium levels can be affected by numerous factors unrelated to sarcoidosis and are not characteristic of this disease process. Therefore, the elevation of calcium levels is particularly indicative of sarcoidosis and its related complications, emphasizing its importance in the diagnosis.