Methods are provided for modulating MRGPR X2 generally, or for treating a MRGPR X2 or a MRGPR X2 ortholog dependent condition, more specifically, by contacting the MRGPR X2 or the MRGPR X2 ortholog by administering to a subject in need thereof, respectively, an effective amount of a compound having structure (I):




or a pharmaceutically acceptable salt, isomer, hydrate, solvate or isotope thereof, wherein W, Z, R1, R2, R3, R4, R5, R6 and Rx are as defined herein. Pharmaceutical compositions containing such compounds, as well as the compounds themselves, are also provided.