Table 1.

The cytokines and chemokines that stimulate AD.

Cytokines	Classification	Role	Reference
IL-4	Th2 cell-derived cytokines	Interacts with keratinocytes to produce eosinophil chemokine (CCL26) in the acute phase. Regulates IgE secretion from B cells. Directly acts on itch sensory neurons to promote pruritus.	[51,52]
IL-13
IL-31	Th2 cell-derived cytokines	Causes pruritus by binding the IL-31 receptor A (IL31RA). Downregulates barrier-associated protein expression. Inhibits keratinocyte differentiation.	[53,54]
IL-1α	IL-1 family	Recruits leukocytes to inflammation sites. Decreases the natural moisturizing factors in stratum corneum layers.	[55,56]
IL-1β
IL-33	IL-1 family	Regulates the activation of mast cells, ILC2, and basophils. Secretes pruritic cytokines from Th2 cells or keratinocytes.	[57,58,59]
IFN-γ	Th1 cytokines	Recruits CXCR3 agonistic chemokines, which induce the T cell into the inflammation site.	[60]
TNF-α
TSLP	IL-7-like cytokines	Promotes dendritic cells to differentiate into naïve T cells. Binds to the TSLP receptor which is placed in cutaneous sensory neurons to induce pruritus.	[61,62,63,64]