The inflammation affects the smaller vessels of the skin such as the capillaries and the medium-size vessels that include venules and arterioles. Small vessel vasculitis is the most common cause ...

They appear on the surface of the skin as thin red or bluish lines and ... some level of damage to small capillaries, venules, and arterioles. Their appearance is often due to a combination ...

You can read all about that, and lupus symptoms here. Spider mites appear as rashes caused by issues with the skin’s arterioles. These are small arteries that supply blood and help regulate heat ...

Vasoconstriction - blood vessels near the surface of the skin called arterioles constrict (become narrower) allowing less blood to the skin surface and therefore less heat is lost by radiation.

This lowers the body temperature. Blood vessels called arterioles near the surface of the skin dilate (get wider) allowing more blood to the skin surface where more heat can be lost by radiation.