Tolerability of ALK Tree Tablet

Inclusion Criteria: * A clinical history of birch pollen induced rhinoconjunctivitis (with or without mild to moderate asthma ) of at least two years prior to trial entry requiring symptomatic treatment during the birch pollen season. * Positive Skin Prick Test response to Betula verrucosa * Positive specific IgE against Bet v1 * FEV1 ≥ 70% of predicted value Exclusion Criteria: * No clinical history of perennial allergic rhinitis and/or asthma caused by an allergen to which the subject is regularly exposed and sensitised * No clinical history of significant recurrent acute sinusitis (defined as 2 episodes per year for the last two years all of which required antibiotic treatment) or chronic sinusitis * No conjunctivitis, rhinitis or asthma at the screening or randomisation visit * No history of anaphylaxis, including anaphylactic food allergy, bee venom anaphylaxis, exercise anaphylaxis or drug induced anaphylaxis * No history of angioedema