What is a Buruli Ulcer?

A Buruli ulcer is a large, disfiguring skin lesion that results from a severe bacterial infection. The bacteria responsible, Mycobacterium ulcerans, is from the same genus of pathogens that cause leprosy and tuberculosis. A person who develops a Buruli ulcer is likely to notice a small, hard, discolored spot on the skin that begins to break open within a few days. Over the course of one to four weeks, the bacteria penetrates deep within the skin and kills dermal, muscle, cartilage, and possibly bone tissue. Immediate antibiotic treatment combined with surgery is essential to prevent major health complications.

Buruli ulcers are very rare in most parts of the world. The bacterium is most prominent in tropical regions of Africa, Asia, Australia, and South America. Relatively little is known about its origin and how it is transmitted to humans, but research suggests that infection is most likely to occur if an open skin wound is exposed to contaminated water or soil. Young children and elderly people who have weaker immune systems are at the highest risk of experiencing active infections.

It may take several weeks or even months for symptoms to appear after being exposed to Mycobacterium ulcerans. The first sign of infection is usually a firm mass that develops just underneath the outermost layer of skin. Bacteria buried within the nodule begin to release a toxin called mycolactone that is deadly to skin cells. A Buruli ulcer eventually develops as skin necrosis occurs. The open wound is typically painless in the early stages, but pain, radiating inflammation, and other symptoms may develop if another infection occurs in the area.

Without treatment, a Buruli ulcer can spread across the skin and into deep tissue. Muscles, nerves, blood vessels, and cartilage can be severely damaged by the bacteria, and some infections also penetrate and kill bone tissue. Severe ulcerations can cover a large area of skin on the legs or arms, sometimes consuming up to 15 percent of a person's total skin surface area. Body-wide symptoms of fever, fatigue, aches, and nausea are likely in the late stages of infection as other types of bacteria invade the exposed wound.

A doctor can usually diagnose a large Buruli ulcer based on its appearance and reported symptoms. If it is still in the early stage, a blood sample and skin biopsy is performed so that lab tests can either confirm or rule out the presence of Mycobacterium ulcerans. Additional tests such as ultrasounds and x-rays may be used as well to determine the extent of damage to tissues underneath the skin.

Treatment for a Buruli ulcer usually consists of a long course of antibiotics, specifically the drugs rifampicin and streptomycin. A developing nodule or small lesion can often be excised with a scalpel to prevent the infection from spreading. If major ulceration has already occurred, there is little doctors can do to prevent the area from becoming permanently scarred and disfigured.