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.
Identification. The blood test used to diagnose rheumatoid arthritis detects rheumatoid factor (RF) antibodies, which tend to be high in people with rheumatoid arthritis, according to Medline Plus.dentification. The blood test used to diagnose rheumatoid arthritis detects rheumatoid factor (RF) antibodies, which tend to be high in people with rheumatoid arthritis, according to Medline Plus.