Histamine is a naturally occurring biogenic amine that plays an important role in the human body. Histamine is involved in many mechanisms through its release, such as immunological, physiological, and inflammatory mechanisms, as well as smooth muscle contraction, vasodilation, and increased vascular permeability. In healthy persons, Histamine in food is rapidly metabolized by the enzyme diamine oxidase (DAO). But in cases where the DAO activity is reduced excess Histamine may generate effects which are quite similar to allergic reactions such as flushing, headache, rhinitis, pruritus, vertigo.