Section 1 Allergic Rhinitis

**3**

**Chapter 1**

**Abstract**

Allergic March

dermatitis to asthma is still a matter of debate.

**Keywords:** allergic march, atopy, children

**1. Introduction**

*Blaženka Kljaić Bukvić, Mario Blekić and Marija Pečnjak*

Atopy is an inherited tendency of producing immunoglobulin E on common proteins from the environment like pollen, house mites and food. The presence of atopy represents a risk for the development of allergic diseases like atopic dermatitis, asthma, allergic rhinitis and food allergy, although atopy can also be present only in the form of asymptomatic sensitization. Allergic diseases share common inherited and environmental risk factors, immunologic patterns of allergen-specific Th2 response and efferent phase of immunologic reaction characterized with the production of IgE and activation of granulocytes. The presence of one disease increases the risk for developing other diseases. Allergic diseases demonstrate characteristic sequence of incidence in childhood which is called allergic/atopic march and starts with atopic dermatitis in early infancy. Disrupted integrity of the skin in atopic dermatitis contributes to the development of sensitization and increases the risk for development of other allergic diseases. The discovery of filaggrin gene mutation opens the possibility for causative incidence of allergic diseases and for prevention of development of atopic march. But, the causal link from atopic

Allergic diseases are the most common chronic condition in childhood. Epidemiological studies observed increase in the prevalence of allergic diseases from the middle of the twentieth century, which is explained by environment and lifestyle changes and improvements in modern Westernized societies. At the beginning of the twenty-first century, stagnation in the prevalence of asthma while increase in the prevalence of food allergy was noticed, which announced the second wave of allergy epidemics [1–3]. The first atopic phenotype that starts in early infancy is atopic dermatitis (AD). It is estimated that it affects up to 20% of children. Disrupted integrity of the skin barrier contributes to the development of sensitization to food and aeroallergens and also increases the risk for the development of food allergy. It is considered that 30% of children with AD have food allergy, and 30% develop asthma and 75% allergic rhinitis [4]. About 3–5% of children have been diagnosed with food allergy, and up to 50% of them have AD [1]. AD and food allergy can coexist and can also appear independently in infancy and in the first years of life. In the following years, wheezing induced by viruses like respiratory syncytial virus or rhinovirus and sensitization to inhalational allergens can be observed. As the child grows up, respiratory symptoms are more common and occur outside of the infection; introduction of anti-inflammatory drugs is needed, i.e., the signs of asthma occur. Preschool and school age are the time of
