If you do develop an ulcer, get treatment right away. Small problems are easier to fix than big ones

Skin ulcers of the lower legs become more common with age for a variety of reasons. The most common ulcers develop when the veins that return blood from the legs deteriorate.

Because blood in the leg veins must run uphill to return to the heart, leg veins come equipped with valves to keep blood from being pulled back down by gravity.

Some people inherit fewer valves or valves that give out early. Valves can be damaged by injury, blood clots (venous thrombosis) or vein inflammation (phlebitis.)

Calf muscles also aid return of blood from the legs. Their contraction squeezes the veins. Injury, immobility or just plain inactivity can impair the leg vein function.

When blood pools in the veins, it backs up blood in the capillaries, the smallest blood vessels that ultimately feed into the veins. Stretching the capillaries damages their walls, releasing substances that cause inflammation.

This damages the skin of the lower legs.

The most common location is near the ankle, especially just above the medial malleolus (the inner ankle bone). At first, the ankles swell. The swelling generally decreases overnight when the patient lies flat, only to progressively worsen over the course of the day. The skin stretches, and develops a rash similar to eczema with redness, dryness, and scaling. The legs often ache. Over time, pigments leaking from the pooled blood discolor and darken the skin. Eventually the skin breaks down to form an irregular shallow ulcer.

Once an ulcer appears, treatment involves compression, leg elevation, dressings, medication, and sometimes surgery. Compression reduces pain and swelling, enhances return of blood from the veins, and hastens ulcer healing. Compression may be elastic, inelastic or mechanical.

Elastic compression conforms to leg size and therefore is effective during both rest and activity. Either stretchable bandages (ace wraps) or compression stockings can be used. Compression stockings are superior because they are capable of applying higher pressure and can be graded to apply the highest pressure near the ankle with decreasing pressure toward the knee and thigh.

Inelastic compression consists of bandages, like an Unna boot, that don’t stretch. While not as effective as elastic compression, there are times when, as a doctor, I find it helpful. The Unna boot is one brand of inelastic compression dressing made of moist gauze impregnated with zinc oxide. The doctor applies it, and it hardens (not as much as a cast) and stays in place until removed several days later.

For the patient who can’t — or won’t — apply compression stockings, it jumpstarts the healing process and ensures that the patient is actually complying with the doctor’s recommendation. But they’re messy, and if the ulcer is draining a lot, they can smell.

Mechanical pressure devices encircle the legs. A pump inflates and deflates them to provide a pumping action. They are expensive and cumbersome and so are used for bedridden patients who can’t tolerate other compression methods.

Leg elevation means getting the legs above the level of the heart. Ideally this happens three to four times daily for 30 minutes at a stretch. That’s not always possible especially for working people. Even lesser degrees of leg elevation speed ulcer healing, and reduce swelling.

There are dozens — if not hundreds — of types of dressings to choose from: hydrocolloids , hydrogels, foams, pastes, and more. But so far studies have not proven any one dressing superior to others. So the best choice is something that isn’t too expensive, is easy to use, and preferred by the patient or doctor.

Infected venous ulcers require antibiotics by mouth. For ulcers without infection, oral antibiotics don’t hasten healing. There is limited evidence for the usefulness of topical antibiotics. In any case, leg elevation, appropriate dressings, and leg compression are the first line treatments.

Large or stubborn venous stasis ulcers sometimes require skin grafting. Fortunately this is rarely needed. There is a role of surgery to treat venous insufficiency to reduce the risk of recurrent venous stasis ulcers.

The financial cost of venous stasis ulcers is huge because nearly 1 percent of the population is affected. The estimated price tag is $2 billion per year in he United States.

If you have leg concerns that may be related to poor vein function, ask your doctor whether you might benefit from compression stockings, vein surgery, or other preventive measures.

And if you do develop an ulcer, get treatment right away. Small problems are easier to fix than big ones.