The type of eczema that commonly affects children, reason for which it is also called infantile eczema is atopic eczema. The term atopic refers to a propensity of certain genetically selected individuals to develop throughout their lives a series of immune-mediated inflammatory diseases; thus the association of eczema, rhinitis, rhinosinusitis, hay fever, conjunctivitis or asthma with atopic eczema in a certain individual is far from being out of the common. There is also a strong familial character of this disease; studies aim at identifying families in which the interrelated conditions mentioned above are present at different members so as to be able to obtain a natural experimental model in order to search for a genetic component. As much as genes could be implied is proved by studies made on homozygous (identical) and also heterozygous twins; chances of a twin having a flare of acute atopic eczema during his life is rendered at about 70% in case his identical twin had one, but only at 20% in case he has an unlike twin brother. In both cases the percentage fails to reach 100%, indicating a strong participation of environmental factors in the development of the condition.
Since the actual cause has not been identified (if there actually is a singular pinpoint cause) in spite of all the clinical research performed so far, treatments cant have an etiologic character; on the contrary, they are either pathogenic (addressing the immune system of the patient, clearly involved in producing the clinical aspects) or symptomatic like for example relieving the itch, or the pain or trying to deal with the inesthetic aspect of the lesion whichever bother the patient at the most.
A troubling aspect regarding this condition is the huge increase in incidence and prevalence over the past few decades especially in highly industrialized countries. The reason for this is the continuous immunological siege that food and cosmetics industry, but not them alone are doing on public health. Although chemicals used within human-aimed products undergo a series of complex testing before finally being approved for use, in genetically predisposed individuals who probably display a hyperactive immune system, these tend to act as antigens either by themselves or by haptenic mechanism. The second implies that smaller chemical pieces, unable to become antigens by themselves bind to plasma proteins and then convert to full antigens, activating the immune system and inducing the clinical response which can be any of the conditions mentioned. Basically numbers show a prevalence of 1 to 3 % among adults in industrialized countries. In case of children as much as 1 in 5 could be affected.