What does histamine produce?

Histamine produces the following effects:

* Vasodilation: Histamine causes blood vessels to dilate, which increases blood flow to the affected area. This can cause redness, swelling, and warmth.

* Increased capillary permeability: Histamine increases the permeability of capillaries, which allows fluid and proteins to leak out of the blood vessels into the surrounding tissues. This can cause edema (swelling).

* Smooth muscle contraction: Histamine can cause smooth muscle contraction, which can lead to symptoms such as bronchospasm (narrowing of the airways) and gastrointestinal cramps.

* Itching: Histamine stimulates the release of pruritogenic factors, which cause itching.

* Pain: Histamine can also cause pain by stimulating the release of pain mediators.