The cause of eczema is not fully understood. But it's believed to be triggered by an overactive immune system that responds aggressively when exposed to irritants.
Eczema is sometimes caused by an abnormal response to proteins that are part of the body. Normally, the immune system ignores proteins that are part of the human body and attacks only the proteins of invaders, such as bacteria or viruses.
An eczema flare-up is when one or more eczema symptoms appear on the skin. Common triggers of eczema flare-ups include:
- chemicals found in cleaners and detergents that dry out the skin
- rough scratchy material, like wool
- synthetic fabrics
- raised body temperature
- temperature changes
- sudden drop in humidity
- food allergies
- animal dander
- upper respiratory infections
Read more at: https://www.healthline.com/health/eczema