Multicenter, cross-sectional study to recruit a random sample of 6000 children via school class registers: 3000 children aged 13-14 years and 3000 children aged 6-7 years.Standard ISAAC core questions for wheezing, rhinitis, and atopic dermatitis will be used. The ISAAC questionnaire has been validated by the World Health Organization and translated into many languages, and used in many countries. In this study, the Arabic and English version will be used. In addition, questions regarding exposure to Arabian incense "Bokhor" and smoking questions of the environmental questionnaire will be included.
ISAAC Questionnaires
1. Core questionnaire on wheezing.
2. Core questionnaire on rhinitis.
3. Core questionnaire on atopic dermatitis.
4. Smoking questions of the environmental questionnaire.
5. Video questionnaire on wheezing (only for 13-14 years age group, if applicable)
