Reddish-brown spot on the shin. What is it?
A reddish-brown spot above the ankle on the shin, or even a larger area of discoloration, is a common occurrence. It is a symptom that draws attention to venous circulatory insufficiency of the lower limb. In medical records the spot is called a “hemosiderin deposition.” Let's review what causes it, how you can prevent it, and whether there is any way to remove it.
The skin “rusting”
The discoloration is actually caused by “rust,” that is, deposited oxidized iron.
It forms when red blood cells leak out of the smallest vessels (capillaries) into the tissues in larger numbers. When these red blood cells break down, the iron released from their hemoglobin turns into hemosiderin. It is stored in the tissue under the skin and appears on the skin as a brown spot. 
What lies behind the discoloration?
The reddish-brown spotting of the lower leg is most often caused by problems related to the veins. Especially when the pressure in the veins of your leg is regularly elevated. This condition may be described by terms such as venous hypertension or venous insufficiency. The high pressure in the vein causes blood cells to be “pressed out” through the vessel wall into the skin tissues. After they break down, a spot forms in the skin tissue.
If your job requires long periods of standing or sitting, you can expect such changes over time. Your risk is also higher if your parents or siblings have similar leg problems, or if they are being treated for varicose veins or leg ulcers.
If at the end of a long day your legs feel heavy (as if you were wearing lead boots), hurt, or become swollen, that is not a good sign. These symptoms indicate hidden venous insufficiency. If brownish-red spots and thinned, dry skin around them have already appeared, you are too late for prevention.
Venous hypertension / venous insufficiency
Your heart pumps blood through the arteries to the rest of your body. Then it returns to the heart through the veins. The circulation of your blood is ensured by your heart, the diaphragm and respiratory muscles, and the contraction of your muscles during movement.
Your veins contain “valves” (so-called venous valves) that allow blood to flow only in one direction (back toward the heart). As long as your veins and their valves close well, they prevent blood from falling back toward your leg.
The problem occurs when these valves weaken or the vein dilates. If this happens, the valve “lets go” and upward blood flow worsens. More and more blood remains in the veins, they swell, dilate and become tortuous (commonly referred to as varicose veins).
If this condition persists, the increasingly swollen vein wall becomes overstretched and begins to “leak,” meaning blood cells escape into the surrounding tissues. At this stage your ankle may be noticeably swollen. Brown spots may appear. Moreover, in more severe cases circulation may deteriorate so much that wounds develop which then heal poorly or only over months. These wounds are called ulcers.
What to do if reddish-brown spots appear on the shin?
If the spots have appeared, you are somewhat delayed. Nevertheless, visit a vascular surgery clinic and request an examination.
You need to determine the severity of the problem. Based on that, treatment can be set up to prevent further deterioration.
At the clinic, in addition to your medical history and physical examination, a Doppler ultrasound may be performed. The essence of this is to determine blood flow in the vessels of your leg using ultrasound. With this method they can measure the speed of blood flow in the main (larger) vessels. They also compare both sides.
Further tests may be necessary to assess diabetes or cardiac involvement.
How can the shin discoloration be treated?
Hemosiderin deposited in the skin cannot be removed, so the discoloration will accompany you for life. What you can do is prevent or at least slow down further deterioration.
Skin hydration
The skin of the discolored area becomes thin, dry and can crack. Avoid drying soaps. Use a moisturizing cleanser or cosmetic. The bathwater should not be too hot, as that can also dry the skin. Do not use rough towels or bath mitts, you can injure the thin skin.
Compression therapy
Two types of compression therapy can be used: elastic stockings made of stretchable material or machine pneumatic massage. The latter can be performed with a device commonly referred to in our country as a compression therapy unit. Compression therapy improves blood flow in the veins. It is very effective in reducing swelling and promoting healing, and in preventing wounds or ulcers.
For the treatment of venous insufficiency and post-thrombotic conditions, the compression therapy unit is the most effective tool. For example, the Power Q-2200 unit may be suitable.
Functional electrical stimulation (FES)
A cheaper method than the compression unit is electrical stimulation of the lower limb muscles. The muscle contractions triggered by the impulses help limb circulation similarly to muscle movement. Favorable results can be expected from 20–30 minutes of treatment daily.
The Myolito multifunctional electrotherapy device, the Rehalito EMS muscle stimulator device or the Elite SII TENS/EMS device may be suitable.
Exercise
I mentioned above that the natural motor of venous blood flow is the regular contraction of muscles, i.e. movement. The best method to stimulate venous circulation with varicose veins is exercise, especially brisk walking, jogging or cycling. Try to move as often as possible. Ideally 20–30 minutes once or twice a day, or a single 40–50 minute session. More is better in this case!
Prevention
Since shin discoloration is a consequence of venous insufficiency, if you don't want reddish-brown spots on your legs, PREVENT THEM! The best method is daily regular exercise. Start in childhood and never stop exercising. (In the previous paragraphs I detailed my recommendations.)
