brimstone - an old name for sulfur. native sulfur, native sulphur. atomic number 16, sulfur, sulphur, S - an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)
These patches of red, and sometimes irritated or itchy, skin can appear anywhere on the body, but they are most commonly found on the arms, neck, and face. These blotchy patches can be caused by a variety of factors, such as weather, genetics, allergies, or environmental conditions.
Causes Of Red Blotches On Arms And Skin. There are many factors that can cause a change in the skins melanin. Allergens to environmental sources, inhaled substances or physical contact can be causes of red blotches on arms and other parts.