Summary: The prevalence of type 2 inflammatory diseases, mainly atopic or allergic diseases such as asthma and atopic dermatitis, is increasing worldwide. They cause not only health problems in patients, but also a significant social and economic burden. Furthermore, patients are often affected by more than one of allergic diseases suggesting a shared underlying mechanism. So it is not surprising to find causal drugs such as monoclonal antibodies. In Poland, there are five medicinal products based on immunoglobulin G, which are used in allergology, i.e. omalizumab, mepolizumab, benralizumab, reslizumab and dupilumab. These biological drugs enable the intensification and some kind of personalization of the therapy based on the complex mechanisms and non-standard pharmacokinetics discussed in this publication.