SYK and infection: The pathogenesis of CSU is multi-factorial, which is reported to be related to genetic factors, the environmental challenges like infections, food intolerance, the activation of coagulation cascade, dysregulation of intracellular signaling pathways within mast cells and basophils [i.e. imbalance of spleen tyrosine kinase (SYK) and Src homology 2-containing inositol 5’ phosphatase (SHIP)] and autoimmunity (Figure 1) (6–10).