Mycetoma


Mycetoma is a chronic subcutaneous infection caused by aerobic actinomycetic bacteria or fungi eumycetoma. While most cases of mycetoma occur in Sudan, Venezuela, Mexico, and India, its true prevalence and incidence are not well-known. It appears most frequently in people living in rural areas, particularly farmers and shepherds. It is listed by the World Health Organization as a neglected tropical disease.

Risk

Frequent exposure to penetrating wounds by thorns or splinters is a risk factor. This risk can be reduced by disinfecting wounds and wearing shoes.

Pathogenesis

Mycetoma is caused by common saprotrophs found in the soil and on thorny shrubs in semi-desert climates. The most common causative agents are:
Infection is caused as a result of localized skin trauma, such as stepping on a needle or wood splinter, or through a pre-existing wound.
The first visible symptom of mycetoma is a typically painless swelling beneath the skin; over several years, this will grow to a nodule. Affected people will experience massive swelling and hardening of the area, in addition to skin rupture and the formation of sinus tracts that discharge pus and grains filled with organisms. In many instances, the underlying bone is affected. Some people with mycetoma will not experience pain or discomfort, while others will report itching and/or pain.

Diagnosis

There are currently no rapid diagnostic tools for mycetoma. Mycetoma is diagnosed through microscopic examination of the grains in the nodule and by analysis of cultures. Since the bacterial form and the fungal form of mycetoma infection of the foot share similar clinical and radiological features, diagnosis can be a challenge. Magnetic resonance imaging is a very valuable diagnostic tool. However, its results should be closely correlated with the clinical, laboratory and pathological findings.

Treatment

While treatment will vary depending on the cause of the condition, it may include antibiotics or antifungal medication. Actinomycetoma, the bacterial form, can be cured with antibiotics. Eumycetoma, the fungal form, is treated with antifungals. Surgery in the form of bone resection may be necessary in late presenting cases or to enhance the effects of medical treatment. In the more extensive cases amputation is another surgical treatment option. For both forms, extended treatment is necessary.
In cats, mycetoma can be treated with complete surgical removal. Antifungal drugs are rarely effective.

Research

For a list of trials that are related to mycetoma, go to this ClinicalTrials.gov link: https://www.clinicaltrials.gov/ct2/results?cond=%22Mycetoma%22