The purpose of the study is to find out if montelukast can be used to treat the various symptoms of allergic syndrome.

Inclusion Criteria:

• Wheal diameter at least 4 mm in skin-prick test for both birch and timothy

• Allergic symptoms in both upper airways (allergic rhinitis) and lower airways (asthma-like symptoms or diagnosed asthma) and at least one of the following:

  • Allergic conjunctivitis
  • Atopic eczema
  • Oral symptoms from vegetables or fruits by cross reactivity to birch
  • Urticaria in allergen exposure

Exclusion Criteria:

• Need for regular treatment with glucocorticoids
• Current smoking
• Other major disease or need for regular drug treatment
• Pregnancy