Venous stasis ulcers are red and have irregular borders, according to Cleveland Clinic. Infected ulcers may secrete yellow or green fluid. Sometimes yellow skin tissue covers the ulcer, or the ulcer feels warm. Discolored, swollen or shiny skin around a venous stasis ulcer is common. Typically found between the knee and ankle, this type of ulcer accounts for 80 to 90 percent of all leg ulcers.
The other two types of ulcers found on the legs are neurotrophic and arterial skin ulcers, explains Cleveland Clinic. Neurotrophic skin ulcers are brown and black or pink and red with calluses surrounding the actual ulcer. Arterial skin ulcers are black, brown, gray or yellow, and are sometimes accompanied by discoloration and swelling on the surrounding skin. Both types of ulcers cause a depression in the healthy skin around them and are more-common on the feet.
Poor blood circulation creates venous stasis ulcers, notes WebMD. Before a venous stasis ulcer forms completely, the skin is dark red or purple and may itch. This discoloration is due to blood pooling within the vein and draining into the surrounding tissue. Patients who recognize these warning ulcer signs should seek medical attention possibly to prevent the ulcer from forming.
If the ulcer does form and becomes infected, the area may smell, according to WebMD. Treatment involves increasing blood circulation, removing dead tissue around the ulcer and prescribed antibiotics when necessary.