PATHOLOGY

Detailed explanation-1: -Type I hypersensitivity is also known as an immediate reaction and involves immunoglobulin E (IgE) mediated release of antibodies against the soluble antigen. This results in mast cell degranulation and release of histamine and other inflammatory mediators.

Detailed explanation-2: -Basophils. These small cells seem to sound an alarm when infectious agents invade your blood. They secrete chemicals, such as histamine, a marker of allergic disease, that help control the body’s immune response. Eosinophils.

Detailed explanation-3: -Histamine is released by mast cells during an allergy attack and can produce multiple biological effects including bronchoconstriction (asthma), vasodilation (watery eyes, runny nose), and gastric acid secretion.