There is usually a family history. The skin readily becomes itchy in response to a number of allergic and non-allergic stimuli, and the pruritus may be disproportionate to the physical signs. High levels of circulating IgE antibodies are very common, as are multiple positive prick tests. There is often a fluctuating course, but most cases clear up to adulthood, the majority within the first 5 years of life. There is much evidence for a genetic basis for the atopic state.
Environmental factors are important determinants of fluctuations.
Wool next to the skin frequently causes irritation. Extremes of climate often worsen the disease. Clinical features Onset is often in the first 3 months of life. Itching is the major symptom and at times there may be little rash. In infancy the skin is often patchily dry and red, with episodes of vesiculation and crusting.