Ragweed sensitization in Egyptian children with bronchial asthma

Abstract

INTRODUCTION Ragweed sensitivity has been recognized as an important allergen causing allergic rhinitis (AR) and bronchial asthma (BA). In the 1930s, ragweed was identified as the major elicitor of hay fever and asthma. About 40 species were defined with Ambrosia artemisiifolia (common or short ragweed) and A. trifida (giant ragweed) being the most common. Among all Ambrosia species, A. artemisiifolia is the most abundant and invasive representing a major cause of allergy in late summer worldwide. Environmental factors such as temperature and CO2 concentrations have great influences on the ragweed pollen production and hence the allergen amount. These two environmental factors are rising due to climate change and urbanization. Weeds are one of the common inhabitants of the plant kingdom as they require less water and can survive under harsh conditions. Egypt is generally characterized with low rainfall and high temperatures and therefore weeds are expected to grow spontaneously in our environment. Allergenic potency of the ragweed pollen is outstanding. A single ragweed plant can release up to one billion pollen grains per season. Such abundant pollen counts can lead to a strong increase of the sensitization rates and emergence of symptoms. It has been reported that as little as 10 pollen grains per cubic meter of air can trigger an allergic reaction. Ragweed pollen grains can travel by several hundreds to thousands of kilometers by air and lead to allergy symptoms in areas where the plant is not actually abundant. Due to their widespread existence and severe impact, ragweed pollen-induced AR and BA significantly affect the quality of life, impeding attendance and school performance. The primary aim of this pilot study was to evaluate the frequency of ragweed sensitization among a group of atopic Egyptian children with Original article