What is Histamine causes: and explain in detail?
The main actions of histamine are: 

Vasodilation
Increased vascular (venular) permeability
Itching 
Pain

Stimulation of mast cells and basophils also releases products of arachidonic acid metabolism including the release of slow reacting substances of anaphylaxis (SRS-As). 
The SRS-As consist of various leukotrienes (LTC4, LTD4 and LTE4).
Mohan H. Textbook of pathology. Jaypee Brothers Medical Publishers; 2015. Edition 7. Page 123