Oxazolone-Induced Dermatitis.

In vivo experiments of chronic mast cell stimulation were performed exactly as previously described (43, 59). Briefly, the ear pinnae of Kit^W-sh/W-sh mice were reconstituted with 2 × 10⁶ WT or KO mast cells. After 4 to 5 wk, sensitization was performed with 20 μL of 2% oxazolone in acetone; after another week, mice were challenged every other day with 0.5% oxazolone for up to seven challenges. As readout of inflammation, ear swelling was measured over time with a dial thickness gauge (Mitutoyo).