The term "allergic march'' might make you think of a parade on a spring day.
But the reality isn't at all lighthearted.
The allergic march is the natural progression of allergic conditions, starting in infancy. Young children who develop disorders like eczema and food allergies are more likely to go on to develop allergic rhinitis and allergic asthma.
This progression may be natural, but that doesn't mean it's inevitable. More and more, allergy experts believe the march can be stopped or at least slowed with proper treatment.
Before a child even walks, the march can begin. Eczema -- the red, itchy skin condition also called atopic dermatitis -- is usually the first allergic condition to show up in susceptible children, often between ages 3 months and 12 months.
Next comes the onset of food allergies that generally peak by age 2. Eczema and allergies to milk, eggs and soy usually improve with age. Allergies to shellfish and nuts tend to persist into adulthood.
Allergic rhinitis, better known as hay fever, and allergic asthma tend to develop during preschool years. Both of these conditions can improve with time but tend to persist, especially if allergy therapy isn't undertaken.
The underlying problem starts when a child's immune system overreacts to common contaminants, such as dust mites, pollens and animal dander.
We're not exactly sure why some children's immune systems react so strongly. But the number of people in Western nations who report allergic symptoms has gone from 10 percent a few decades ago to nearly 30 percent today. More awareness and improved diagnostic tools, as well as family history, pollution and stress, all may play a role.
A major theory these days is the "hygiene hypothesis" -- the idea that when children are exposed to infections, especially parasites, at an early age, their immune systems develop normal responses. But children raised without those exposures may wind up with immune systems that have shifted away from fighting infections and toward attacking harmless exposures like dust mites and pollens.
What can we do to interrupt this allergic march? Given the worldwide increase in allergies, scientists have been researching this topic feverishly.
Primary prevention of allergic disease before a child is born has been fraught with conflicting data. Breast-feeding exclusively for the first four months of life may have some positive effect on the development of allergic disease; other studies indicate it has no effect for good or ill.
Delaying the introduction of solid foods until 4 months of age remains a current recommendation regarding food allergies, although that may change as more light is shed on the issue.
It is much clearer that maternal smoking during pregnancy and during the baby's early life directly correlates with recurrent wheezing and the possible development of food allergies in infancy. Much research is being done on exposure to probiotics and early exposure to animals in the home.
Secondary prevention measures target those children who are considered at risk due to family history and other factors, or show early signs of allergic disease.
Allergic asthma is the most severe of these disorders and, if not properly treated, can lead to long-term lung damage. An allergist should closely follow any children with conditions like food allergies or eczema.
There is data to suggest that by intervening early with allergen immunotherapy (allergy shots) or possibly even antihistamines, we may be able to prevent the allergic asthma from ever developing, or at least control its severity. Treating asthma early and aggressively can optimize normal lung development and prevent long-term damage.
Nobody should be permitted to smoke in the home of a child with asthma. If an allergic child reacts to animals, pets need to be relocated. Children can't just pop a pill to control an allergic reaction; the inflammation their bodies produce can cause significant long-term damage.
(Mona Mangat is board certified in allergy/immunology, pediatrics and internal medicine. She lives in St. Petersburg, Fla.) Article from the St. Petersburg Times.