What inflammation can lead to the presence of protein in urine?

The presence of protein in urine, known as proteinuria, is often associated with nephritis, which is inflammation of the kidney. When the kidneys are inflamed due to nephritis, their filtering capability can be compromised. This affects the glomeruli, the tiny filters in the kidneys that normally prevent large molecules like proteins from passing into the urine. In nephritis, the inflammation can lead to increased permeability of these filters, allowing proteins such as albumin to leak into the urine. This is a significant indicator of kidney dysfunction and an important diagnostic feature in conditions affecting kidney health.

In contrast, the other conditions mentioned—otitis (ear inflammation), dermatitis (skin inflammation), and peritonitis (inflammation of the peritoneum)—do not directly impact the kidneys or their ability to filter blood. While systemic inflammation may have various effects on overall health, it is nephritis that specifically alters kidney function in a way that leads to protein being present in urine.