Diagnosing Repeated Lower Extremity Ulcerations

Author(s): 
Guest Clinical Editor: Tamara Fishman, DPM

A patient’s medical history can provide you with critical information that is necessary to differentiate among the various types of lower extremity ulcerations. Not only are there many different etiologies of lower extremity ulcers, it’s also important to be aware of the patient’s underlying medical conditions as well, as you will see in the following case study. A 38-year-old Caucasian female patient recounted her underlying medical conditions when she came in for evaluation and treatment of her left leg ulceration. She injured the side of her leg while walking and had the ulceration for about a month. She noted that she has had ulcers in this area in the past. The patient says the last time she had the same exact ulceration, it took a little over a year to heal. Her past medical history is significant for osteoporosis, rheumatoid arthritis, microcytic anemia and lower extremity edema. She also noted that she had many blood transfusions when she was in her 20s. This patient is young and very active, which makes it difficult for her to remain off her feet. She explained that the more swelling she has in the lower limb, the more pain she feels. What Is The Diagnosis? 1. Sickle cell anemia 2. Rheumatoid arthritis 3. Thalassemia 4. Pyoderma gangrenosum Possible Answers 1. Sickle cell anemia is not the correct answer. Sickle cell anemia is a chronic hemolytic anemia occurring almost exclusively in African-Americans. It is characterized by sickle-shaped red blood cells caused by homozygous inheritance of Hb S. With the sickling and capillary plugging with deformed red blood cells, the surrounding tissue becomes ischemic with tissue necrosis and ulceration occurs. You’ll usually see these sickle cell ulcers below the knee. They are usually chronic, shallow and develop in relation to a sickle cell crisis. You’ll notice a typical “punched-out” appearance with well-defined wound edges. The tissue bed is usually granulating. Keep in mind that these ulcers usually appear in patients with more severe anemia. Debridement of any necrotic tissue and maintaining a moist wound environment should enhance wound healing. In some cases, using an Unna boot may be effective to promote wound closure. If all other treatments have failed, you may try to perform skin grafting. Also be aware that when a patient is having a sickle cell crisis localized to the extremities, it may mimic osteomyelitis, acute arthritis (such as gout) or rheumatoid arthritis. 2. Rheumatoid arthritis is not the correct answer. It is a chronic, multi-system disease of unknown etiology. The characteristic feature of rheumatoid arthritis is persistent inflammatory synovitis. The peripheral joints are involved in a symmetric distribution. Patients with severe manifestations of rheumatoid arthritis may also suffer from rheumatoid vasculitis, which can affect any organ system in these patients. In its most aggressive form, rheumatoid vasculitis can cause polyneuropathy, cutaneous ulceration, dermal necrosis and digital gangrene. Large ischemic ulcerations develop in the lower extremity. The pathogenesis of these types of ulcers is not well understood. These particular ulcers may take a long time to heal. (Also keep in mind that Felty’s syndrome characteristically comprises rheumatoid arthritis, leukopenia and splenomegaly. About one-quarter of these patients are affected by large refractory skin ulcerations.) Vasculitic ulcers are often associated with infiltration and inflammation of small vessels in the skin. These ulcers are most often associated with patients who have inflammatory conditions such as rheumatoid arthritis, scleroderma and systemic lupus erythematosus. Characteristically, these ulcers are painful and may be multiple and confluent. A biopsy may be necessary to confirm the diagnosis. Small vessel vasculitis accounts for about 10 to 20 percent of lower leg ulcerations in rheumatoid arthritis. Prednisone in combination with methotrexate has been proven successful in managing rheumatoid vasculitis. 3. Thalassemia is the correct answer. Thalassemias are a group of chronic inherited microcytic anemias characterized by defective Hb synthesis and ineffective erythropoiesis. Thalassemia is more common in people of Mediterranean, African and Southeast Asian ancestry. This ulcer did reoccur after a minor injury to the affected area. 4. Pyoderma gangrenosum (PG) is not the correct answer.

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