The study physician will inform the subject and his or her guardian about the study and gives the subject information (Appendix 1). Guardian’s written informed concent (Appendix 2) will be obtained after he or she has got acquainted with the test procedure. The subject can withdraw the consent to the study at any time. Guardian will be asked to fill the modified ISAAC questionaire (Appendix 3). New patients will enter the study at 8-10 a.m. and p.m.