Etiology two broad types a① Allergic asthma:(gE) Histamine Ag-Ab- mast cell surface Trapase mediators release Leukotrienes Prostaglandins → muscle contraction pA vascular leakage mucus hyper secretionEtiology----- two broad types  ①Allergic asthma: (IgE) • Ag-Ab → mast cell surface • → mediators release • → muscle contraction • vascular leakage • mucus hyper secretion • Histamine Trapase Leukotrienes Prostaglandins PAF