1 Cold hands and Itching skin and Cold feet (10 causes). 2  Cold hands and Itching skin and Weakness (10 causes). 3  Cold hands and Itching skin and Breathing difficulties (9 causes). 4  Cold hands and Itching skin and Confusion (9 causes).
Rheumatoid factor (RF) Rheumatoid factor (RF) is a blood test that measures the amount of the RF antibody in the blood. Most of the time, blood is drawn from a vein located on the inside of the elbow or the back of the hand. In infants or young children, a sharp tool called a lancet may be used to puncture the skin.
Rheumatoid factor. Overview. A rheumatoid factor test measures the amount of rheumatoid factor in your blood. Rheumatoid factors are proteins produced by your immune system that can attack healthy tissue in your body. High levels of rheumatoid factor in the blood are most often associated with autoimmune diseases, such as rheumatoid arthritis and Sjogren's syndrome.