**3.1 Experimental protocol**

Experimental protocol for ICD induction is graphically summarized in Figure 3. Naive mice are exposed at day 0 to a single application of 20 µl of DNFB 0.5% in a 4:1 mixture of acetone and olive oil applied on the left ear, while the same volume of vehicle alone is applied on the right ear as a control. Six days after ear sensitization, ear thickness is measured with a digital calliper. Analysis can be performed similarly to ACD model (see section 2.1).
