Erythema and ecchymosis are both skin conditions involving discoloration, but the key difference lies in the cause and appearance of the discoloration. Erythema is redness caused by increased blood flow, while ecchymosis is a bruise caused by blood leakage under the skin.
Detailed Breakdown
To further illustrate the differences, consider the following aspects:
| Feature | Erythema | Ecchymosis |
|---|---|---|
| Cause | Increased blood flow to the skin | Blood leaking from damaged blood vessels |
| Appearance | Redness; skin blanches with pressure | Bruise; color changes over time (red/purple/black/blue/green/yellow); does not blanch with pressure |
| Size | Can be localized or widespread | Typically localized |
| Symptoms | Warmth, possible itching or pain | Tenderness, possible swelling |
| Common Causes | Sunburn, inflammation, allergic reactions | Trauma, bleeding disorders, medications |
Erythema Explained
Erythema is essentially redness of the skin. This redness occurs when blood vessels close to the skin's surface become dilated, leading to increased blood flow. When you press on skin with erythema, it temporarily turns white (blanches) before returning to red. Examples include sunburn, allergic rashes, and some infections.
Ecchymosis Explained
Ecchymosis, commonly known as a bruise, happens when small blood vessels under the skin break and leak blood into the surrounding tissues. The blood becomes trapped, causing the characteristic discoloration. Unlike erythema, ecchymosis does not blanch with pressure, and its color changes over time as the body breaks down the blood. Bruises are often caused by trauma, but can also indicate underlying bleeding disorders or medication side effects.
In short, erythema is redness due to increased blood flow, while ecchymosis is a bruise resulting from blood leakage under the skin.
