Mycetoma

Mycetoma is a chronic subcutaneous infection caused by aerobic actinomycetic bacteria (actinomycetoma) 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 (WHO) 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:

 Madurella mycetomatis (fungus)
 Nocardia brasiliensis (bacteria)
 Actinomadure madura (bacteria)
 Streptomyces somaliensis (bacteria)
 Actinomadura pelletieri (bacteria)

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 (lump). 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 share similar features, diagnosis can be a challenge.

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 and surgery. 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

References

External links 

 DermNet NZ: an online resource about skin diseases from the New Zealand Dermatological Society Incorporated.
 Orphanet: a reference portal from Europe that provides information on rare diseases and orphan drugs.

Category:Animal fungal diseases
Category:Infectious diseases
Category:Neglected diseases
Category:Tropical diseases