Abstract: Compounds that interact with the histamine H4 receptor, and which may be useful for treating or preventing disorders and conditions mediated by the histamine H4 receptor, e.g. inflammation, are of formula (I) wherein Q is CR1 or N; X is CR2 or N, provided that Q and X are not both N; Y is CR3 or N; Z is CH or N; R1, R2, R3, R4, R5 and R6 are independently H, F, Cl, Br, I, or a hydrocarbon group which optionally contains one or more heteroatoms; and R7 is a heterocyclic radical including one or more N atoms; or a pharmaceutically acceptable salt, ester or solvate thereof.