All the keywords in this study were classified into 11 clusters (Figure 8): #0 “sensitization,” #1 “intranasal corticosteroids,” #2 “eczema,” #3 “IgE,” #4 “airway inflammation,” #5 “allergy immunotherapy,” #6 “hyperactivity,” #7 “IL-10,” #8 “pump spray,” #9 “clinical benefit,” and #10 “immunotherapy.” According to Figure 8, keyword clusters such as “sensitization,” “airway inflammation,” “allergy immunotherapy,” and “hyperactivity” appeared in 2002, and persisted for 20 years. Here, IGHE is linked to inflammatory response.