In the life of a child there are some “Kodak moments”. You may also call them “Ahaa” moments – when the child gives the first smile to the mother, when the child takes the first tentative step, when the child starts to walk or when she for the first time says “mama”. These are great landmarks in the life of a child !!
In the life of an allergic child, apart from these normal “Ahaa” moments, there are some “Oh no” moments too. For example, when it is discovered that the child is allergic to milk and has colic on drinking milk. Or later when there is development of eczema, sneezing attacks or constant runny nose or wheezing and breathing difficulty.
It is a common observation that children who have an allergic tendency show signs of allergy sequentially. This is called the “allergic march”. Food allergies usually appear earliest. So a child might have colic or eczema due to milk. This usually starts at infancy to 2 years of age. Next to come is allergic rhinitis which is characterized by runny or blocked nose and terrible sneezing. This usually happens at age 3-6 years. Around the same time or slightly later, asthma may also appear.
They may appear sequentially, so that the earlier form of allergy disappears when the new one appears. Or they can run concurrently – for example sneezing and runny nose was already there and asthma also starts troubling.
But there is good news ! Just as these things appear sequentially, they may also disappear at a certain age. A lot of children fortunately outgrow their allergies at around puberty. This can happen in 50% of the boys and 40% of the girls.
Imagine you are watching the march at a 26th you is the army contingent, then the tanks roll in followed by the air-show. The allergic march is also like that.
Why do allergies appear in a preordained sequential pattern ?
We know that for allergy to develop there has to be a predisposition to allergy and there has to be an exposure to the allergen. For instance, one cannot develop allergy to penicillin without being exposed to it.
The immune system of a new born first encounters food allergens thru the gut. Common allergens at this stage are milk, egg and wheat. The manifestations of allergy are in the form of intestinal colic and skin allergy.
Air borne allergens- pollens and house dust- are encountered later. They have to interact with the immune system for at least two years for sensitization to occur. Hence allergic rhinitis and asthma develop a little later.
Scientist and doctors are now studying this allergic march deeply with the hope to intervene in this cycle so that this allergic march can be halted or averted.