Mycetoma (Madura Foot)

Causes

Mycetoma is caused by organisms that live in soil and plants. They enter the body through small injuries, such as a thorn or splinter, so the feet of people who walk barefoot or work in fields are most often affected. More than 50 organisms can cause it.

Who gets it

• people in rural areas of Africa (especially Sudan), Latin America (especially Mexico), India and other tropical regions, the so-called mycetoma belt
• farmers, herders and laborers who walk barefoot
• men aged 20 to 40 most often, though children are also affected

It is not contagious from person to person. In 2016 the World Health Organization added mycetoma to its list of neglected tropical diseases.

Symptoms

Mycetoma develops slowly over months to years:

1. a small, firm, painless nodule under the skin at the site of a minor injury
2. gradual swelling of the area
3. formation of multiple sinuses, small openings that discharge pus, blood and grains (tiny clumps of the organism)
4. spread to deeper tissues, muscle and bone, causing deformity

The foot is involved in about 70 percent of cases. The hand, leg, knee, back, buttocks and head can also be affected. Pain is usually minimal until bone is involved or a secondary infection occurs. Mycetoma of the head, neck or back can spread inward and be life-threatening.

Diagnosis

• examination of the grains from discharge or tissue under a microscope, including their color and shape
• culture to identify the organism
• biopsy of deep tissue
• molecular tests (PCR) to identify the species
• imaging: X-rays show bone damage, and ultrasound or MRI show the extent of disease and the characteristic "dot-in-circle" sign on MRI

Telling eumycetoma from actinomycetoma is essential because treatment is completely different. Conditions that can look similar include chronic bacterial osteomyelitis, tuberculosis, chromoblastomycosis, sporotrichosis and tumors.

Treatment

Actinomycetoma (bacterial)

Treated with long courses of antibiotics, often combinations such as trimethoprim-sulfamethoxazole with amikacin, or other regimens. Treatment usually lasts many months. Cure rates are generally good with adherence.

Eumycetoma (fungal)

Harder to treat:

• long-term antifungal medicines, such as itraconazole, for months to a year or more
• surgery to remove infected tissue, often after antifungals shrink the lesion
• amputation in advanced cases that do not respond

Recurrence after treatment is common in eumycetoma, so follow-up is important.

General care

• treating secondary bacterial infections
• wound care
• physical therapy after surgery

Complications

• spread to bone, causing destruction and deformity
• secondary bacterial infections
• disability, inability to walk or work
• amputation
• rarely, spread to internal organs from lesions on the head or trunk

Prevention

• wearing shoes and protective clothing when walking or working in fields
• cleaning and covering minor wounds
• seeking care early for any persistent painless swelling

Frequently asked questions

What is mycetoma?

Mycetoma is a chronic infection of the skin, deeper tissues and bone, usually on the foot. It is caused by fungi or bacteria that enter through a small wound and form a painless swelling with draining sinuses containing grains. It is mainly found in rural tropical regions.

Is mycetoma contagious?

No. Mycetoma does not spread from person to person. People catch it from soil and plants when organisms enter through small injuries, such as a thorn prick.

Can mycetoma be cured?

Bacterial mycetoma (actinomycetoma) can usually be cured with long courses of antibiotics. Fungal mycetoma (eumycetoma) is harder to cure and often needs antifungal medicines plus surgery, and it can recur. Early diagnosis improves results.

Why is mycetoma painless?

The infection grows slowly and causes little inflammation in the early stages, so pain is usually minimal. Pain often appears later when bone is involved or a secondary bacterial infection develops. This is why people often delay seeking care.