The dermatitis or eczema atópico is a dermatitis, inflammation of the skin, which is characterized by cutaneous injuries with eritema descamación, vesicles, exudation, fissures, injuries of scratched and increased areas (liquenificación), almost always with itch. These injuries appear in different stadiums in the shape of badges that can appear depending on the age in the face, the flexuras of extremities, or in diverse areas of the body, even in some patients in the whole extension of the skin (eritrodermia).

The dermatitis atópica presents before herself of different forms and distribution depending on the age of the patient.

• In the nursing one, before the first year of age eczema injuries usually appear in the head (milk crust), in the face respecting eyes, nose and mouth, or extended by the skin of the whole body. In this form of appearance it is usually a very showy and intense picture but his prognosis is very good disappearing before 5 years.
• In the children of school age the eczema injuries prevail in the flexuras of extremities, in the neck and in the area of behind the ears, sometimes with eczema injuries in the lips and the eyelids.
• In the adult there are two forms, one owes to the persistence of the eczema of the school child with injuries flexurales predominantly, and other of appearance in the adult with spread injuries, often eritrodérmicas with big affectation of the face and neck and that tends to the cronificación.
• There are other minor forms of the eczema atópico, as for example:
• White Ptiriasis: There are whitish injuries in the skin with scales and skin dries, can appear in the face or distributed by the whole body.
• Queilitis atópica: There are eczema injuries in the lips with fisuración.
• Pulpitis atópica: It appears with descamación and fisuración of the fleshy parts of hand fingers and feet.

The eczema atópico turns out to be more frequent in persons with precedents of allergic illnesses in to the family (rinitis, asthma, conjunctivitis or eczema), also they usually have the IgE high, typical of the allergic patients.
This high IgE can be unspecific, that is to say an allergy is not to mites, pólenes or food, or if to be specific to one or several of them.

This high IgE usually notices to inflammatory cells (mastocitos and basófilos) and before specific stimuli (food, mites pólenes, etc...) or unspecific (stress, changes of temperature, moisture, irritants of the skin) they produce the liberation of Histamine accumulated inside this one cells producing itch.
This intense itch initiates the sequence of spontaneous or secondary injuries to the plastered one and for it the eczema forms.

In the patients with eczema atópico a decrease of the immunity exists against certain cutaneous infections for it the eczema usually becomes infected and cronificarse a second time.

The symptoms typical of the eczema atópico are:

• Intense itch of cutaneous areas, principally flexuras of the extremities.
• Skin dries and with descamación.
• Eczema injuries with eritema descamación, vesicles, exudation, fissures, injuries of scratched and increased areas (liquenificación).
• The distribution of the injuries corresponds to the age of appearance and intensity of the eczema as we have seen earlier.

Once characterized like eczema atópico for the familiar allergy precedents in the family and for the distribution and symptoms typical of this eczema, it is a question of looking for the causes of the underlying allergy that produces histamine liberation.
As the cause of liberation of the histamine is the fixation of the IgE to diverse allergens, it is necessary to realize an allergy study to know the causes.

In most cases there is appreciated the elevation of the circulating entire IgE in blood.
From here it is necessary to determine the possible allergy especificidad to food (egg, milk, fish, fruits, vegetables, dry fruits, etc...), mites and pólenes by means of skills of determination of specific IgE (CAP, RAST, etc...).

Also allergy tests they can realize in the skin by means of prick test, or even by means of test epicutáneos.
The target is to find specific allergic factors that cause the itch to exclude them from the ambience of the patient, for it sometimes it is necessary to verify the relation food addition causes effect by means of exclusion diets, verifying the improvement and worsening on having eliminated or to add the suspicious food.