mycetoma

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Mycetoma

 

Definition

Mycetoma, or maduromycosis, is a slow-growing bacterial or fungal infection focused in one area of the body, usually the foot. For this reason—and because the first medical reports were from doctors in Madura, India—an alternate name for the disease is Madura foot. The infection is characterized by an abnormal tissue mass beneath the skin, formation of cavities within the mass, and a fluid discharge. As the infection progresses, it affects the muscles and bones; at this advanced stage, disability may result.

Description

Although the bacteria and fungi that cause mycetoma are found in soil worldwide, the disease occurs mainly in tropical areas in India, Africa, South America, Central America, and southeast Asia. Mycetoma is an uncommon disease, affecting an unknown number of people annually.
There are more than 30 species of bacteria and fungi that can cause mycetoma. Bacteria or fungi can be introduced into the body through a relatively minor skin wound. The disease advances slowly over months or years, typically with minimal pain. When pain is experienced, it is usually due to secondary infections or bone involvement. Although it is rarely fatal, mycetoma causes deformities and potential disability at its advanced stage.

Causes and symptoms

Owing to a wound, bacteria or fungi gain entry into the skin. Approximately one month or more after the injury, a nodule forms under the skin surface. The nodule is painless, even as it increases in size over the following months. Eventually, the nodule forms a tumor, or mass of abnormal tissue. The tumor contains cavities—called sinuses—that discharge blood-or pus-tainted fluid. The fluid also contains tiny grains, less than two thousandths of an inch in size. The color of these grains depends on the type of bacteria or fungi causing the infection.
As the infection continues, surrounding tissue becomes involved, with an accumulation of scarring and loss of function. The infection can extend to the bone, causing inflammation, pain, and severe damage. Mycetoma may be complicated by secondary infections, in which new bacteria become established in the area and cause an additional set of problems.

Diagnosis

The primary symptoms of a tumor, sinuses, and grain-flecked discharge often provide enough information to diagnose mycetoma. In the early stages, prior to sinus formation, diagnosis may be more difficult and a biopsy, or microscopic examination of the tissue, may be necessary. If bone involvement is suspected, the area is x rayed to determine the extent of the damage. The species of bacteria or fungi at the root of the infection is identified by staining the discharge grains and inspecting them with a microscope.

Treatment

Combating mycetoma requires both surgery and drug therapy. Surgery usually consists of removing the tumor and a portion of the surrounding tissue. If the infection is extensive, amputation is sometimes necessary. Drug therapy is recommended in conjunction with surgery. The specific prescription depends on the type of bacteria or fungi causing the disease. Common medicines include antifungal drugs, such as ketoconazole and antibiotics (streptomycin sulfate, amikacin, sulfamethoxazole, penicillin, and rifampin).

Prognosis

Recovery from mycetoma may take months or years, and the infection recurs after surgery in at least 20% of cases. Drug therapy can reduce the chances of a re-established infection. The extent of deformity or disability depends on the severity of infection; the more deeply entrenched the infection, the greater the damage. By itself, mycetoma is rarely fatal, but secondary infections can be fatal.

Prevention

Mycetoma is a rare condition that is not contagious.

Resources

Periodicals

McGinnis, Michael R. "Mycetoma." Dermatologic Clinics 14, no. 1 (January 1996): 97.

Key terms

Biopsy — A medical procedure in which a small piece of tissue is surgically removed for microscopic examination.
Grains — Flecks of hardened material such as bacteria or fungi spores.
Nodule — A hardened area or knot sometimes associated with infection.
Secondary infection — Illness caused by new bacteria, viruses, or fungi becoming established in the wake of an initial infection.
Sinuses — Cavities or hollow areas.
Tumor — A mass or clump of abnormal tissue, not necessarily caused by a cancer.

mycetoma

 [mi″sĕ-to´mah]
an initially localized, slowly progressive, destructive infection of the cutaneous and subcutaneous tissues, fascia, and bone, caused by certain actinomycetes (actinomycotic mycetoma) or true fungi (eumycotic mycetoma). It usually involves the leg or foot (Madura foot), but the hand or any other site may be affected. There is swelling accompanied by formation of granulomas, suppurating abscesses, and multiple sinuses. Called also maduromycosis.

my·ce·to·ma

(mī'sē-tō'mă),
A chronic infection involving the subcutaneous tissue, skin, and contiguous bone; characterized by the formation of localized lesions with tumefactions and multiple draining sinuses. The exudate contains granules that may be yellow, white, red, brown, or black, depending on the causative agent. Mycetoma is caused by two principal groups of microorganisms: 1) actinomycetoma is caused by actinomycetes, including species of Streptomyces, Actinomadurae, and Nocardia, 2) eumycetoma is caused by true fungi, including species of Madurella, Exophiala, Pseudallescheria, Curvularia, Neotestudina, Pyrenochaeta, Aspergillus, Leptosphaeria, Plemodomus, Polycytella, Fusarium, Phialophora, Corynespora, Cylindrocarpon, Pseudo-chaetosphaeronema, Bipolaris, and Acremonium. Synonym(s): Madura boil, Madura foot, maduromycosis

mycetoma

/my·ce·to·ma/ (mi″sĕ-to´mah) a chronic, progressive, destructive infection of the cutaneous and subcutaneous tissues, fascia, and bone caused by traumatic implantation of certain actinomycetes (actinomycotic m. ), true fungi (eumycotic m.), or other organisms; it usually involves the foot (Madura foot) or leg.

mycetoma

(mī′sĭ-tō′mə)
n. pl. myceto·mas or myceto·mata (-mə-tə)
A chronic, slowly progressing bacterial or fungal infection usually of the foot or leg, characterized by nodules that discharge an oily pus.

my′ce·to′ma·tous (-tō′mə-təs, -tŏm′ə-) adj.

mycetoma

[mī′sətō′mə]
Etymology: Gk, mykes + oma, tumor
a severe fungal infection involving skin, subcutaneous tissue, fascia, and bone. One kind of mycetoma is Madura foot.
enlarge picture
Mycetoma

mycetoma

Mycology A slow, relentless, ulcerating fungal–true fungi infection which, when neglected, may result in osteomyelitis, in a background of impaired host defense, most common in the feet of young ♂–5:1 who work in the tropics/subtropics, which may be seen in the thigh and shoulders; clinical disease is rare unless accompanied by bacterial infection. See Pulmonary aspergilloma.

my·ce·to·ma

(mī'sĕ-tō'mă)
1. A chronic infection involving the feet characterized by the formation of localized lesions with tumefactions and multiple draining sinuses. The exudate contains granules that may be yellow, white, red, brown, or black, depending on the causative agent. Actinomycotic mycetoma is caused by bacterial species in the actinomycetes group; eumycotic mycetoma is caused by true fungi.
Synonym(s): Madura boil, maduromycosis.
2. Any tumor with draining sinuses produced by filamentous fungi.

mycetoma

A hard tumour-like mass of fungus, or of bacteria that form fungus-like colonies, in the foot or leg. There are multiple channels (sinuses) that discharge pus. The condition is confined to people living in poor conditions in the tropics. Surgical drainage and antibiotics may succeed, but amputation is often the only resource.

mycetoma

; eumycetoma; maduromycosis Madura foot

mycetoma

chronic granulomatous infection of the skin and underlying tissues, with edema, draining sinuses and grains, giving the appearance of a tumor. May be caused by bacteria (actinomycetoma) or fungi (eumycetoma).

actinomycotic mycetoma
containing filamentous bacteria of the order Actinomycetales.
blackgrain mycetoma
a mycetoma may contain small, dense masses of necrotic material, some of them calcified. They may be yellow or white or black—hence blackgrain mycetoma.
eumycotic mycetoma
mycetoma containing fungi.
maduromycotic mycetoma
a disease of humans, but with a similar disease in horses and dogs. The common findings in lesions are the fungi Curvularia geniculata, Petriellidium boydii (syn. Allescheria boydii, Monosporium apiospermum). In horses Brachycladium spiciferum has also been identified. Characterized by an extensive distribution of mycetomas. The name originated from a commonly associated fungus Madurella spp.
white-grain mycetoma
caused by non-pigmented fungi, such as Neotyphodium spp. and Pseudallescheria spp.