A validated mobile Allergen exposure chamber (AEC) is used to expose qualified study participants suffering from house dust mite (HDM) induced allergic rhinoconjunctivitis. A maximum of four individuals are exposed at a time under standardized conditions with a mixture of allergens from Dermatophagoides pteronyssinus and Dermatophagoides farinae (each 50%, faeces and body allergens; doses of 250 μg/m3 air; 21°C, and 55% relative air moisture). After the first exposure, a dietary supplement lozenge, containing beta-lactoglobulin (BLG), iron, retinoic acid, zinc and polyphenols, is taken twice daily for a period of 12 weeks, followed by the second exposure. A minimum of thirty persons are challenged with HDM allergen. After entering the chamber there is an acclimatization phase of 20 minutes with no exposure. Exposure time starts after acclimatization in the chamber and is 120 minutes at each visit. Objective parameters are recorded every 30 minutes, and subjective parameters are recorded every 10 minutes over a period of 120 minutes. During the exposure a plateau (steady-state) of total nasal symptom score with a difference from baseline is measured in all participants for each of the two exposures with HDM.

Inclusion Criteria:

• Allergy to house dust mite (HDM) with rhinoconjunctivitis symptoms with/without asthma. These allergic symptoms must have been present for at least 2 years and severity assessed by anamnesis according to ARIA guidelines (mild; moderate/severe - Bousquet et al, 2007)
• Positive skin test to HDM extract using a skin testing diagnostic product used in the daily routines of the clinics, with a wheal diameter > 3 mm
• Positive nasal provocation test to HDM allergen as used in the chamber and/or a history of TNSS ≥ 3 after 120 min HDM exposure in the chamber
• Oral and written informed consent

Exclusion Criteria:

• Current or previous treatment with allergy vaccination within the last two years.

• Concomitant (or newly developing during study period) severe disease interfering with allergy testing

• Co-medication interfering with allergy testing for other diseases, e.g. immunosuppressants, oral and/or nasal corticosteroids, chromones and pregnancy

• Clinically relevant co-sensitization to early blossoming tree pollen allergens, and cat allergens

• Patient with FEV1 < 80% of predicted value prior to exposure

• Patients with severe asthma and / or with a history of uncontrolled asthmatic attacks in the last three months before the selection process

• Patients with an upper intestinal tract disease, where the local examiner believes that taking the dietary supplement could pose a risk to the patient

• History of serious chronic medical conditions and/or any disease where, in the opinion of the site investigator, participation in the trial would pose a risk for the patient

• Treatment prior to study visits and during the whole study time with:

  • systemic corticosteroids within three weeks (21 days)
  • topical nasal corticosteroids within two weeks (14 days)
  • chromones within 7 days
  • antihistamines within 72 hours before visit 1
  • antibiotics within 3 months before visit 1 and during the whole study
  • anti-allergic drugs during the whole study time.

Study group recruitment is based on an existing data base of subjects suffering from HDM-induced allergic rhinoconjunctivitis reacting positively to chamber exposure with HDM and by advertising for volunteers.