The first episode of atopic eczema can be delayed to adulthood the majority of people have a history that goes back to their childhood. About half of affected children show improvement by the age of six and 60 per cent by the age of 14.
About 60 per cent of people have a family history of at least one of the atopic conditions. This points to genetic links to atopy but the relationship is complex. A combination of genetics and environmental exposures probably determine whether an individual develops atopic eczema, but we do not yet know what the most important influences are.
Main symptom, as with all types of eczema, is itch. Generally the skin is dry but the most affected skin looks red (itch and a bit pain), with a slightly raised but ill-defined margin when the eczema is active. Lumps or blisters, some oozing of fluid from the skin surface and scaling of the skin are all features of flare-ups. After the acute episodes the skin will settle down, which is a bit less irritating looks but shows more in the way of thickening, scoring and darkening of the skin where it is most scratched.
Children usually affects the face and as they get a bit older the rash spreads to the body and limbs. The napkin area is usually spared although it may be inflamed from the effect of urine or the overgrowth of yeast organisms on the skin (thrush). White children tend to get the most trouble on the flexures- the skin creases on the meeting surfaces of the joints. Elbows, wrists, behind the knees and fronts of the ankles are typical. Black and Asian children tend to be affected on the opposite side of the joints, such as the point of the elbow or front of the knees. Adults show more involvement of the face and trunk again.
Superficial infection of the skin causes increased redness and heat, weeping and perhaps crusting. Small blisters may contain pus. Infected eczema does not usually give signs of general infection such as a raised temperature.
For the severe cases they may even faint or go unconscious.
Tests The diagnosis of atopic eczema is usually quite straightforward on the basis of the symptoms, appearance and positive family history of atopy. Although blood tests will be likely to show generally raised levels of the IgE antibody this is not in itself either necessary or helpful to the doctor. The IgE RAST test (a blood test) looks at more specific allergens such as general food groups, house dust mite and animal dander. However, these should be interpreted with caution and may only be useful for a proportion of individuals with eczema. Your doctor may perform a range of other allergy tests if he or she believes them to be beneficial.