Chronic stress induces mast cell degranulation and increases substance P in the skin of atopic dermatitis mice more than normal mice

Background : Atopic dermatitis (AD) is one of skin diseases that involve psychological stress. So we placed an AD mouse model and control mice under chronic repetitive stress and determined epidermal thickness, mast cell degranulation rates, and substance P (SP) levels. Objective : Our aim was to clarify the mechanism that chronic stress aggravates AD. Methods : AD like mice and control were placed under restraint stress for two hours per day for two weeks by immobilizing them in a restrainer. We measured epidermal thickness, mast cell degranulation rates, and SP levels. Results : After chronic stress, the control mice demonstrated only a slight increase in mast cell degranulation rates and SP levels in the skin tissue, with no changes in epidermal thickness. However, AD like mice showed a marked elevation in both degranulation rates and SP levels as well as increased epidermal thickness (P < 0.05). Conclusion : These results indicate that there are differences in chronic stress responses between control and AD like mice, that is consistent with clinical data showing that AD patients are more susceptible to stress.