Results
Type 2 inflammation and related
diseases
The experts agreed that a simple definition of the underlying
immunopathology of type 2 inflammation is Th2 cell and/or ILC2
activation with expression of type 2 inflammatory cytokines such as
IL-4, IL-5 and IL-13 (Table 1). In addition, type 2 inflammation can be
characterised by the elevation of biomarkers such as IgE, blood and/or
tissue eosinophils, and, in asthma, elevated FeNO. Type 2 inflammation
may be considered as an underlying immunopathological driver of some
endotypes of asthma, atopic dermatitis, chronic rhinitis, CRSwNP and
eosinophilic esophagitis.
The published epidemiological evidence suggests that there is some
overlap in the occurrence of asthma, atopic dermatitis, chronic
rhinitis, CRSwNP and eosinophilic esophagitis in adults (Table 2) and in
the occurrence of asthma, atopic dermatitis, chronic rhinitis and
eosinophilic esophagitis in children (Table 3). However, in both
populations, the available evidence is too heterogenous to permit valid
conclusions to be drawn about the extent of the overlap.
It was acknowledged that asthma and atopic dermatitis can coexist in
adults and children, that asthma and chronic rhinitis coexist in some
adults and children and that asthma and CRSwNP coexist in some adult
patients. In addition, patients with adult-onset asthma and CRSwNP have
a distinct subset of asthma that often presents clinically with a
disease that is more difficult to manage compared with other subsets of
asthma. However, consensus was not achieved regarding the pattern of
overlap between asthma, atopic dermatitis, chronic rhinitis and CRSwNP
with or without eosinophilic esophagitis. During the virtual meeting,
consensus might have been reached if the consensus statement had been
revised to ‘pattern of selected overlap’, to clarify that patients
rarely have all these diseases simultaneously.
In the experts’ clinical experience, the presence of more than one
atopic disease such as asthma, atopic dermatitis, chronic rhinitis,
CRSwNP or eosinophilic esophagitis often predisposes patients to more
severe disease compared with patients suffering from only one of these
diseases. In addition, in the experts’ clinical experience, type 2
inflammation may drive mild, moderate and severe forms of asthma, atopic
dermatitis, chronic rhinitis, CRSwNP and eosinophilic esophagitis. Some
overlap between asthma, atopic dermatitis, chronic rhinitis, CRSwNP and
eosinophilic esophagitis may be considered as a set of related
multimorbid conditions driven by underlying type 2 inflammation.