IGHE and asthma: In all three studies, HDM SPT reactivity was inversely associated with total IgE/HDM‐specific IgE ratios (rural: 0.05 [0.03, 0.08], p < .001; urban: 0.05 [0.03, 0.10], p < .001; asthma study: 0.03 [0.02, 0.04], p < .001), and HDM‐specific IgG4/IgE ratios (rural: 0.32 [0.19, 0.55], p < .001; urban: 0.17 [0.11, 0.28], p < .001; asthma study: 0.04 [0.02, 0.09], p < .001) [Figure 2C].