3. Allergen exposure/allergen-specific immunotherapy. 3.2. Mites.

Level of recommendation	Statement
A/B	Background: Previous studies did not show that reducing the allergen content in the home environment was a reliably effective method for primary allergy prevention. Studies on the correlation between the early exposure to house dust mites, animal dander, and endotoxins and the later development of asthma and/or allergic sensitizations show partially contradicting results.
	Recommendation: Interventions to reduce exposure to house dust mite allergens in the home, e.g., by using mite allergen-proof mattress covers (encasings) should not be used with the aim of primary prevention. (B)
	In patients with an existing mite allergy, mite allergen reduction measures should be used, as there is proof of effectiveness. (Tertiary prevention). (A)
Level of evidence	Callesen 2014 (2+); O`Connor 2018 (2++); Lynch 2014 (2+); Karvonen 2014 (2+); Karvonen 2019 (2+); Thorne 2015 (4); Loo 2018 (level of evidence not indicated)
Level of consensus:	Consensus