Eczema and Dermatitis
Eczema and dermatitis are essentially the same disorder. Eczema comes from the Greek, meaning a boiling up because the skin appears filled with fluid, while dermatitis means inflammation of the skin, and comes from the Latin. In the past eczema was used to describe those skin conditions for which there was no apparent outside cause, while dermatitis was the term used to cover specific allergy, but since the effects on the skin are the same the terms are now used interchangeably. There is reddening, scaling and itching, together with the formation of fluid filled blisters called vesicles which, when they’re scratched, cause the skin to weep. There are a number of different causes: atopic eczema commonly occurs in people who have an allergic tendency and who often also suffer from conditions such as asthma and hay fever. There may be other members of the family who suffer similarly. It is due to over-production of one of our antibodies, called IgE, which sensitises the cells that contain histamine, called mast cells, which are situated in the skin around blood vessels. It usually affects the inside of the elbows and the backs of knees, but in the infant under the age of one it can affect the cheeks and the fronts of the arms and legs; in the older child the front of the elbows and knees. In chronic cases where there has been persistent scratching the skin in these areas can become thickened, a process called lichenifiation. Testing for allergy by using skin tests, when substances are placed on the skin to see if they elicit a reaction, are commonly positive in response to such things as cat fur or house dust mite.
Eczema in infancy may make its first appearance when the child is exposed to cow's milk protein, as part of the milk protein sensitivity syndrome (see the section on immunity). Avoidance of cow's milk before the age of two is recommended by some authorities in order to prevent the development of eczema, since this may persist even after avoidance of cow's milk.
Contact dermatitis is the name given to the condition where there is an eczematous reaction in the skin in response to contact with an outside agent such as nickel (Levi's dermatitis is patches of eczema on the buttocks where the studs at the back of Levi's jeans have been in contact with the skin). Many substances can cause contact dermatitis, such as latex, washing powders - particularly those containing biologically active ingredients. The skin of infants and young children is very sensitive, and so it might be best to use only the mildest ingredients to clean it.
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