Atopic eczema

Atopic eczema

Atopic eczema is the most common form of eczema and tends to run in families. ‘Atopic’ is a term used to describe the tendency to develop eczema, asthma and hay fever. Some people may only have atopic eczema but others may also have asthma and/or hay fever.

Atopic eczema usually starts in childhood and it can improve as the child gets older, but it can also return at any time, as eczema is a chronic condition. If you have atopic eczema at an early age, your skin is likely to remain sensitive even if there is no recurrence of eczema.

Research has identified genetic mutations of a protein called filaggrin in approximately 50% of people with atopic eczema, which lead to a number of changes in the skin. There is often a lack of filaggrin, which acts to bind cells together in the top layer of skin (the stratum corneum). There is also less fat and oil and fewer natural moisturising factors in the skin, and some cells (the corneocytes) have an irregular shape. Together, these differences result in gaps between the skin cells and an altered skin barrier, which then offers insufficient protection, allowing entry to bacteria, irritants and allergens and leading to increased water loss.

In people with white skin, atopic eczema often affects the creases of body joints, such as the back of the knees and the inside of the elbows, while in people of colour the pattern is often reversed, with atopic eczema affecting the front of the knees and the outside of the elbows. However, atopic eczema can occur all over the body. It causes dry, reddened or darkened skin that may be very itchy, scaly or cracked.

Constant scratching can split the skin, which may lead to infection – usually characterised by weeping or wet eczema, with yellow crusts.

If someone has been scratching the same area for a long time, the skin will thicken, causing what is known as lichenification. The skin looks like leather and can take weeks or months to return to its normal thickness. Lichenification can also cause changes in skin colour, creating darker or lighter patches which eventually fade. Fortunately, most scratched skin heals well over time and scarring is unusual unless scratching has been intense.

For more information on atopic eczema, please download our Living with Eczema and Childhood Atopic Eczema booklets, below.