Changes to the Skin Barrier and Sweating
People with eczema have alterations to the skin barrier in the topmost layer of their epidermis, the stratum corneum. The structure of the skin is different due to changes in the filaggrin gene, which controls the skin barrier structure.
These structural changes make it difficult for the cells to retain water, causing them to shrink. As natural moisturizing factors decrease, the skin becomes dry, and faps open up between cells.
There’s also a breakdown of lipid lamellae, a membrane of tissue that plays a role in water diffusion in the skin. This also contributes to dry skin and a defective skin barrier, making it possible for irritants to easily enter the skin and water disappears through it, the situation is known as transepidermal water loss (TEWL) [4].
Researchers have discovered that TEWL increases during the night, which explains why people with eczema experience worse itching at night.
Sweating when you have eczema would only aggravate your condition and worsen itching. Experts indicate this is as a result of changing sensations in sweat gland nerve endings in the skin and an increase in the number of chemical mediators called neuropeptides.