Although the major part of the damage from atopy is going on within the body, the skin does reveal aspects of the disease process in a wide range of symptoms, from simple dryness of the outer layer to colourful spots and loose flakes with pus.

In general, the first indication of atopic response seen in a child is eczematous patches behind the knees and within the arms inside the elbow.  There may also be some unexplained crying or slight colic, but the skin reaction is the clearest indicator of atopic reaction.

Beyond this initial identification of atopy through the occurrence of eczema, there is a huge range of skin disorders, each with its particular terminology. The complexity of this nomenclature tends to obscure the fact that these disorders arise from very simple causes and, usually, from an immune reaction to one or two food groups – often foods of bovine origin.  Any irritation to the skin is then able to bring about a massive inflammatory response through the complement reaction, triggered by the local release of histamine.  The initial irritation may be mechanical, thermal, chemical, or through exposure to some biological materials.

The first step to dealing with atopic skin conditions is almost always dietary.  Much time and money can be wasted on skin tests, clinical examination, and skin treatments, but the arrival of an atopic skin condition should be seen as a signal to investigate dietary changes.  While dietary change is investigated and implemented, the skin should be protected with simple emollients.  In time, it will be realised that changing the diet has reduced the skin irritation to the extent that emollients are no longer required.  There should be no extended use of corticosteroid application.  This can cause skin damage and obscure the results of the dietary approach to curing an atopic symptom.

There is a medical view that some children simply grow out of eczema.  This is a very simplistic view.  Eczema is just one visible symptom of atopic illness, but if the eczema should cease to be apparent, some other symptoms are likely to be developing in the next phase of the same atopic illness.  The spectrum of symptoms may include, for example, asthma, tonsillitis, glue ear,  or some behavioural pattern, or obesity.  All signs of the atopic disease process at work.