Figure 1: Schematic protocol for oral and aerosol challenge in sensitized mice and lung histology. BALB/c mice were sensitized with ovalbumin (OVA) in Al(OH)3 (day 0) and with OVA (day 14). They were subjected to drink water (control group and aerosol group) or OVA (oral group and oral/aerosol group) for 20 days (days 21 to 41). For 6 days (days 36 to 41), mice (aerosol group and oral/aerosol group) were aerosolized with OVA or saline (control group and oral group). Lung HE staining for each group is shown. Scale bar means 20 μm.