How are S&S of Type I HS caused by different mast cell mediators?

The chemical mediators released by mast cells collectively cause the inflammation and signs and symptoms associated with type I HS reactions. Histamine (mucus secretion and tear formation, itching and sneezing (action on nerves), vasodilation (hives, headache, angioedema, hypotension)) Bronchiole constriction (wheezing, dyspnea, coughing, and cyanosis) vomiting (due to cerebellum stimulation by serotonin and histamine) Smooth muscle relaxation (Intestinal) Type I Immediate HS reactions are mediated by IgE, but T and B cells play important roles in the development of these antibodies. (primary cells are mast cells and eosinophils)