As head of Americaâs largest oil company, Mr. Tillerson has earned a friendship award from Russia and voiced skepticism about American sanctions that have halted some of Exxon Mobilâs biggest projects in the country.
Top 10 facts about the world. Welts are bumps in the skin that are caused by a fluid buildup directly below the surface of the skin. A number of things can lead to the development of a welt, ranging from trauma to the skin to an allergic reaction.
Causes. The welts that come with hives arise when certain cells release histamine and other chemicals into your bloodstream. Doctors often can't identify the reason for this skin reaction, or why it sometimes turns into a long-term problem (chronic hives). But the skin reaction may be triggered by: 1  Pain medications. 2  Insects or parasites. 3  Infection. 4  Scratching. 5  Heat or cold. 6  Stress. 7  Sunlight.