The prevalence of childhood allergic diseases, such as allergic asthma, allergic rhinitis, and atopic dermatitis, has increased exponentially.
Atopic March, sometime called Allergic March, refers to the natural history or typical progression of allergic diseases that often begin early in life. These include atopic dermatitis (eczema), food allergy, allergic rhinitis (hay fever) and asthma.
Relative prevalence of the symptoms according to age
(Many children exhibit symptoms simultaneously)
The Usual pathway for allergy march is Eczema -> Gastrointestinal disorder (Food allergy) -> Rhinitis (Nasal allergy) -> Asthma
However because of genetic variability the march of event can be unpredictable and this is the reason why many suffer from rhinitis alone or asthma alone or have eczema alone.
Time line of allergy march
As the child grow, so also their atopy for example eczema is most likely to occur between birth and 3 month of age. Food allergy is most common in second year of life, nasal allergy manifest itself between ages 3 and 7 year. Asthma onset most likely to occur when a youngster is between 7 to 14 years.
Asthmatic wheezing may already be observed during early infancy. The majority of early wheezers turn out to be transiently symptomatic, whereas in a minority the wheezing may persist throughout school age and adolescence. However, the understanding of the natural history of childhood asthma is still limited, and numerous data sets support the existence of various asthma phenotypes in childhood.
During the first three years of life, the presence of wheezing is not related to elevated serum IgE levels or specific sensitization, and a positive parental history of atopy and asthma seems to be of minor predictive value during the first two years of life.
Those who have persistent wheezing show an association with early sensitization to food and subsequent sensitization to aeroallergens. In addition, the association with a positive family history for atopy and asthma in first-degree relatives becomes stronger.