Understanding the skin of Atopic Dermatitis Sufferers
To better understand how the skin of atopic dermatitis sufferers is associated with symptoms, it may help to understand healthy skin.
The outer layers of healthy skin, called the stratum corneum (SC), serves as the barrier between the body and the outside environment. Healthy SC prevents the water in our skin from exiting into the environment and prevents bacteria, irritants and allergens from entering the skin and causing health problems such as skin irritation.
The design of the SC is similar to the design of a brick wall, and is called a “brick and mortar pattern”. This design is the reason for the healthy barrier, which keeps out harmful substances. In our skin, dead skin cells, called corneocytes, serve like the bricks in a wall and a lipid matrix serves as the mortar. The dead skin cells contain a high concentration of small molecules, which help them hold water, making it difficult for the body’s water to escape. Likewise, the lipid matrix seals the gaps between the dead cells of the SC. Since the lipid matrix is hydrophobic, this prevents water from escaping, as well as irritants and allergens from entering.
Unfortunately, the lipid film in the stratum corneum is deficient in atopic dermatitis skin, which leads to bacteria, irritants and allergens from entering the skin and causing health problems such as skin irritation, which are the main symptoms in AD.
One final characteristic of healthy skin is pH. Healthy skin has a low pH, slightly less than 5.0. This pH level is known to promote growth of healthy bacteria and hamper the growth of harmful bacteria, like Staphylococcus aureus, on the skin. However, the pH of Atopic dermatitis skin has a higher pH of about 7. This higher pH can supports the growth of harmful bacteria.
(from 1st source listed below)
One final characteristic of healthy skin is the pH. Healthy skin has a low pH, slightly less than 5.0. This pH level is known to hamper the growth of harmful bacteria, like Staphylococcus aureus, on the skin.
Source: Structure of the skin barrier and its modulation by vesicular formulations
Prog Lipid Res. 2003 Jan;42(1):1-36. doi: 10.1016/s0163-7827(02)00028-0.
Source: Natural skin surface pH is on average below 5, which is beneficial for its resident flora
Int J Cosmet Sci. 2006 Oct;28(5):359-70. doi: 10.1111/j.1467-2494.2006.00344.x.
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