Autoerythrocyte sensitization (Gardner-Diamond syndrome; painful bruising syndrome) causes painful bruises, usually on the arms or legs.

Autoerythrocyte sensitization is rare. It typically occurs in white women who are experiencing emotional stress.

Doctors are not sure of the cause. One theory is that red blood cells escape from the blood vessels and cause an allergic-type reaction that leads to the bruising. However, most affected people also have symptoms of mental disorders.

People develop episodes of painful bruising. Bruises may develop spontaneously or after injury or surgery. Bruising can occur on different sites of the body from where the injury occurs. Bruises then resolve after a few days. Some people also have nausea, vomiting, and headaches.

Doctors first do tests of the blood clotting system. If the results are normal, doctors may then inject a small sample of the person's own red blood cells into the skin. They also inject a control site with a salt solution that will not cause a reaction. After 24 to 48 hours, doctors examine both injection sites to determine whether there has been a reaction to the red blood cells.

Bruises resolve on their own. Some people benefit from treatment to help them deal with emotional stress.

Last full review/revision January 2013 by David J. Kuter