The skin is the largest organ of the body and carries out multiple critical functions to keep us healthy

This includes acting as a barrier against microorganisms, helping to regulate our temperature control, protecting against UV radiation, and helping to maintain our fluid balance. 

The skin is made up of three layers: the epidermis, dermis, and subcutaneous layer, also known as the fat layer1.


The top layer or epidermis – which itself comprises several different layers – acts as a barrier preventing irritants and allergens penetrating the body and contributes to the immune function. 

The dermis is the skin’s workplace and includes sweat glands for temperature regulation, hair follicles and the sebaceous glands which produce natural oils that keep the hairs clear of dust and bacteria.

This is made up of connective tissue and fat and is the interface between the skin and internal tissue. Veins and other blood vessels are in this layer, too. Working together, these layers of skin provide a physical barrier, prevent loss of moisture, protect against UV radiation, provide sensory feedback, help regulate temperature, help detect infections and produce vitamin D.


Anything which disrupts the skin barrier can accelerate moisture loss and impair the skin’s ability to maintain a healthy equilibrium between the outside world and our inner body.

Dry skin becomes thinner and more fragile, which increases the risk of damage from irritants, allergens, and infectious agents such as bacteria and fungi. Inflammation also increases the risk of damage to the skin barrier.

Once the skin barrier has been breached, the resulting damage can take many forms.


1 [last accessed 18 Aug 2021]