Question Al is a validated question (UK-working party), (Williams et al., 1994a). See
also the section on Atopy, page 22. Questions A2 and A4 about atopic rhinitis (hay
fever) and asthma are commonly used in these forms in Nordic surveys. Question A3
about eye-symptoms is slightly modified from other questionnaires (e. g. the Tuohilampi
questionnaire and the Copenhagen Allergy Study) and can be used to strengthen the
definition of atopy.
Defining a history of atopic dermatitis can be based on positive answer to question Al.
In the Nordic countries, also national questions on atopic dermatitis can be used (see