2,4-Dinitrofluorobenzene (DNFB) induced allergic contact dermatitis model is widely used in the research of inflammation, immune response and pruritus. However, there are several modeling cycles of DNFB model in many literatures, which brings some confusion for choice in the experiments. Here, we established two-weeks and five-weeks models of DNFB and aimed to compare and evaluate them.
Two-week and five-week DNFB models were established in male SPF C57BL/6 mice.
The results showed that the scratching bouts of the ACD mice in two groups both significantly increased. Following the modeling process, the skin of the neck and back of the modeling site of the ACD mice in two-weeks group gradually appeared erythema, edema, ulceration, scabbing, scaling and dryness. The skin surface features of ACD mice in five-weeks group obviously showed erythema, edema, ulceration, scabbing, scaling, re-scabbing, re-scaling, harden and dryness.The whole modeling process are both accompanied by severe scratching reaction after the skin repeated exposure to DNFB. Moreover, the results of hematoxylin-eosin (HE) staining showed that the two modeling methods both had thickened epidermis (p < 0.001) and hyperkeratosis. The toluidine blue (TB) staining revealed obvious inflammatory cell infiltration (p < 0.0001) in two groups.
In our opinion, the two modeling methods both are feasible. The two-weeks ACD model had a shorter modeling period, and while the 5-weeks model could have enough time to observe the effect of drug. Our results provided further experimental basis and evidence for animal models of skin pruritus and inflammation.