The prevalence of childhood asthma, allergic rhinitis and atopic dermatitis in yerevan

Aim-The aim of this research was to explore the prevalence of childhood asthma, allergic rhinitis and atopic dermatitis via standardized methods in Yerevan, which allow comparing our results with the international data.

Methods- We have delivered standardized questionnaires of  ‘The International Study of Asthma and Allergies in Childhood' (ISAAC) to 3079 parents of 6-7 years old pupils (73% response rate) and 3002 13-14 years old pupils (94% response rate) from a random sample of 52 schools of Yerevan in october-december 2008. During the second phase we have also investigated the respiratory function in the current wheezing group (98 and 105 pupils in 6-7 and 13-14 age groups respectively), transient wheezing group (122 and 116) and control group (30 in each age group) with the use of portable spirometer and bronchial reversibility test (two puffs of salbutamol àerosol were used to measure the reversibility).

Results-The lifetime prevalence of wheezing was 9% in 6-7 years old children and 8.4% in 13-14 years old children. Current wheezing (i.e. wheezing in past 12 months) was observed in 3.7% and 4% first and ninth grade schoolchildren, and self-reported doctor diagnosed asthma was observed in 0.5 and 0.8% respectively.

In the younger age group the prevalence of lifetime rhinitis was 6.2%, current rhinitis-4.3%, and doctor diagnosed allergic rhinitis-1%.For the older group the data were-11.7%, 8.5% and 1.9% respectively.

The prevalence of atopic eczema in the 6-7 old age group was 2.4% current eczema-1.4%, and diagnosed atopic eczema 0.6%. In the older age group the lifetime prevalence of eczema was 4.4%, current eczema-3.2% and diagnosed atopic eczema-1.1%.

The spirometry results show that there is no statistically significant difference of forced expiratory volume in 1 second (FEV1) between the wheezing and control groups, but the bronchial reversibility was statistically higher in wheezing group (both age groups p=0.001 and p< 0.0005 for 6-7 and 13-14 age groups respectively).

Conclusion-Our data conclude that Yerevan is a region of low prevalence of asthma and other atopic disorders, but since the prevalence of the symptoms of these diseases is several times higher than diagnosed diseases, we can conclude that allergies are underdiagnosed in Yerevan.