Eczema and Dermatitis are different words for the same skin condition
Skin condition : Eczema (Dermatitis)
What is it?
Eczema and Dermatitis are different words for the same skin condition. Both are derived from Greek. Eczema means ‘to boil over’ and Dermatitis means ‘skin (Derma) inflammation (itis)’.
To understand eczema you need to understand a bit about how the skin works. The top layer of skin is called the epidermis. This layer works as a barrier to prevent water evaporating out leading to dry skin and to prevent irritants such as bacteria, fungi, chemicals from getting in. All of the components within the epidermis working together are known as the skin barrier. The skin barrier includes
In addition to the skin barrier the skin contains millions of immune cells. There are more immune cells in the skin than in the blood. There are many different types of immune cells but they can be roughly divided into four groups.
Eczema occurs when the skin barrier is not working properly and foreign antigens ( e.g microscopic proteins), which can be almost anything not normally found in the body, enter the skin. These are detected by the immune system and an inflammatory response is triggered. The inflammation that occurs in eczema leads to:-
There are many different sorts of eczema but they are all due to a combination of a reduced skin barrier or an overactive immune response. A very poor skin barrier with a relatively normal immune response can lead to bad eczema as can a relatively normal skin barrier but a very overactive and sensitive immune response.
Why have I got it?
Anyone can develop eczema. The types of eczema are generally divided in to endogenous (due to genetic factors) and exogenous ( due to external factors).
These types of eczema are thought to be determined by inheriting a genetic susceptibility. There is often a family history. There may be associations with other diseases such as the association between atopic eczema, asthma and hayfever.
All of the components of the skin barrier are determined to some degree by genetics. Every protein has a genetic code and in some cases there are variations in the codes. Gene variations can lead to proteins which do not work as well as they should. In 2010 researchers in Dundee discovered genetic variations in a protein called filaggrin which is an important component of the skin barrier. They found that mutations in the filaggrin gene led to the production of an abnormal filaggrin protein that did not work as well resulting in a less effective skin barrier. Patients with severe eczema were found to be far more likely than unaffected patients to have filaggrin mutations. They also found that patients with a dry skin condition called icthyosis also had mutations in their filaggrin genes.
In addition to problems with filaggrin mutations they also found that we all have a different number of copies of the filaggrin gene. We all have between 20 and 24 copies of the fillagrin gene. Even if there are no mutations someone with only 20 copies is 2 to 3 times more likely to have dry skin and eczema than someone with 24 copies. This may well explain why many people who do not normally have eczema can develop problems when the skin barrier is put under stress either by too much hand washing or in the winter when the air is dry with low humidity.
Some doctors believe that genetic variations can lead to differences in the activity in the immune system in the skin. This is quite possible although the gene variations that determine this have not been identified.
Types of endogenous eczema include
These eczema are generally triggered by exposure to external substances. Anyone can develop an exogenous eczema regardless of their genetic make up.
Types of exogenous eczema include
Comparing the treatment options
Help from your GP
If you are unsure of the diagnosis you must visit your GP or family doctor. Various other skin rashed can look like eczema. It is important not to confuse a fungal infection with eczema and equally important not to mistake psoriasis for eczema as the treatments are different.
Once a diagnosis of eczema has been established your GP may offer the following
Help from a Dermatologist
A visit to a Dermatologist is needed if there is any doubt about the diagnosis or if standard treatments given by the GP are not effective. Following diagnosis a Dermatologist may offer other options:-