Which statement regarding histamine is incorrect?

The statement that histamine is not a problem with most upper respiratory inflammatory diseases is incorrect because histamine is indeed a significant factor in such conditions. In upper respiratory inflammatory diseases, such as allergic rhinitis and sinusitis, histamine release from mast cells contributes to symptoms like nasal congestion, sneezing, and itching. During an allergic response, histamine is released in larger quantities, leading to vasodilation and increased vascular permeability, which both play a major role in the inflammatory process.

The other statements accurately reflect the functions of histamine. It is well-known for its significant role in allergic responses, promoting symptoms such as inflammation and itching. Additionally, histamine is crucial for gastric acid secretion, stimulating parietal cells in the stomach to produce hydrochloric acid necessary for digestion. Furthermore, histamine does cause blood vessel dilation, contributing to the redness and swelling associated with inflammation.