What Is Hemosiderin Staining?
Hemosiderin staining is a type of chemical reaction between hemoglobin (the blood protein) and iron ions (iron atoms). Iron reacts with hemoglobin to form ferritins. Ferritins are then bound together into red blood cells called erythrocytes. Hemoglobin contains two types of oxygen carriers: O 2 -carrying hemoglobins and O 3 -carrying haptoglobins. Hemoglobin carries oxygen from the lungs to all parts of the body including the skin, hair follicles, kidneys and other organs.
The presence of iron ions in hemoglobin causes it to react with iron atoms within haptoglobins. These reactions cause ferritin molecules to bind tightly to iron atoms on their surface. The result is that these ferritins have a reddish color due to the binding of iron atoms onto them.
A few examples of substances that can stain or discolor blood include:
Blood clots (hemolysis) – these are formed when platelets (a type of white blood cell) break down haptoglobin molecules. They may stain the blood if they remain attached to the erythrocyte for long periods of time. Blood transfusions – some red blood cells carry oxygen only while others contain both oxygen and carbon dioxide gas which makes them very sensitive to hemoglobin stains. For this reason, the iron atoms that bind to hemosiderin do not bind to carbon dioxide. Warming blood – the presence of too many red blood cells in one place causes them to become warm and agitated which can cause them to break down too fast.
When the blood stains the skin or other organs it may cause several different pigmentary disorders. These effects depend on the amount of hemosiderin and blood that is retained by the organs. These include the following:
Erythism – this condition causes patchy red or skin discoloration due to the red blood cells and their breakdown products being trapped within the dermis. The presence of hemosiderin causes a change in skin color from normal skin tone to red or dark brown. When hemosiderin causes the skin to turn red, it is normal for the skin to become slightly darker in some locations. When this happens, the skin has a blotchy appearance. This is called erythrulosis or erythrosis.
The most common places for erythrulosis include the skin of the face, neck, upper chest, lower arms and legs. Others include the scalp, forehead, ears and back of the hands. This condition can also cause hyperpigmentation, a darkening of the natural skin color.
The main symptoms of the disorder are:
Hemosiderin is present in the blood vessels of the skin along with red blood cells. This can result in red spots or areas that look irritated.
The skin may itch, peel or be painful to the touch.
There may be a change in skin color (hyperpigmentation). The skin may lose color in some places (hypopigmentation) or turn red or dark brown and have a blotchy appearance.
Erythrulosis treatment involves the use of several different creams to prevent the skin from being affected by the hemosiderin that is being broken down. This condition is very common in people who have a lot of blood vessel disease and those who suffer from liver disease.
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